foundationdb/fdbserver/DataDistribution.actor.cpp

/*
 * DataDistribution.actor.cpp
 *
 * This source file is part of the FoundationDB open source project
 *
 * Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "flow/actorcompiler.h"
#include "flow/ActorCollection.h"
#include "DataDistribution.h"
#include "fdbclient/SystemData.h"
#include "fdbclient/DatabaseContext.h"
#include "MoveKeys.h"
#include "Knobs.h"
#include <set>
#include "WaitFailure.h"
#include "ServerDBInfo.h"
#include "IKeyValueStore.h"
#include "fdbclient/ManagementAPI.h"
#include "fdbrpc/Replication.h"
#include "flow/UnitTest.h"

class TCTeamInfo;

struct TCServerInfo : public ReferenceCounted<TCServerInfo> {
	UID id;
	StorageServerInterface lastKnownInterface;
	ProcessClass lastKnownClass;
	vector<Reference<TCTeamInfo>> teams;
	Future<Void> tracker;
	int64_t dataInFlightToServer;
	ErrorOr<GetPhysicalMetricsReply> serverMetrics;
	Promise<std::pair<StorageServerInterface, ProcessClass>> interfaceChanged;
	Future<std::pair<StorageServerInterface, ProcessClass>> onInterfaceChanged;
	Promise<Void> removed;
	Future<Void> onRemoved;
	Promise<Void> wakeUpTracker;

	TCServerInfo(StorageServerInterface ssi, ProcessClass processClass) : id(ssi.id()), lastKnownInterface(ssi), lastKnownClass(processClass), dataInFlightToServer(0), onInterfaceChanged(interfaceChanged.getFuture()), onRemoved(removed.getFuture()) {}
};

ACTOR Future<Void> updateServerMetrics( TCServerInfo *server ) {
	state StorageServerInterface ssi = server->lastKnownInterface;
	state Future<ErrorOr<GetPhysicalMetricsReply>> metricsRequest = ssi.getPhysicalMetrics.tryGetReply( GetPhysicalMetricsRequest(), TaskDataDistributionLaunch );
	state Future<Void> resetRequest = Never();
	state Future<std::pair<StorageServerInterface, ProcessClass>> interfaceChanged( server->onInterfaceChanged );
	state Future<Void> serverRemoved( server->onRemoved );

	loop {
		choose {
			when( ErrorOr<GetPhysicalMetricsReply> rep = wait( metricsRequest ) ) {
				if( rep.present() ) {
					server->serverMetrics = rep;
					return Void();
				}
				metricsRequest = Never();
				resetRequest = delay( SERVER_KNOBS->METRIC_DELAY, TaskDataDistributionLaunch );
			}
			when( std::pair<StorageServerInterface,ProcessClass> _ssi = wait( interfaceChanged ) ) {
				ssi = _ssi.first;
				interfaceChanged = server->onInterfaceChanged;
				resetRequest = Void();
			}
			when( Void _ = wait( serverRemoved ) ) {
				return Void();
			}
			when( Void _ = wait( resetRequest ) ) { //To prevent a tight spin loop
				if(IFailureMonitor::failureMonitor().getState(ssi.getPhysicalMetrics.getEndpoint()).isFailed()) {
					resetRequest = IFailureMonitor::failureMonitor().onStateEqual(ssi.getPhysicalMetrics.getEndpoint(), FailureStatus(false));
				}
				else {
					resetRequest = Never();
					metricsRequest = ssi.getPhysicalMetrics.tryGetReply( GetPhysicalMetricsRequest(), TaskDataDistributionLaunch );
				}
			}
		}
	}
}

ACTOR Future<Void> updateServerMetrics( Reference<TCServerInfo> server ) {
	Void _ = wait( updateServerMetrics( server.getPtr() ) );
	return Void();
}

class TCTeamInfo : public ReferenceCounted<TCTeamInfo>, public IDataDistributionTeam {
public:
	vector< Reference<TCServerInfo> > servers;
	vector<UID> serverIDs;
	Future<Void> tracker;
	bool healthy;
	bool wrongConfiguration; //True if any of the servers in the team have the wrong configuration
	int priority;

	TCTeamInfo( vector< Reference<TCServerInfo> > const& servers )
		: servers(servers), healthy(true), priority(PRIORITY_TEAM_HEALTHY), wrongConfiguration(false)
	{
		serverIDs.reserve(servers.size());
		for(int i=0; i<servers.size(); i++)
			serverIDs.push_back(servers[i]->id);
	}
	virtual vector<StorageServerInterface> getLastKnownServerInterfaces() {
		vector<StorageServerInterface> v;
		v.reserve(servers.size());
		for(int i=0; i<servers.size(); i++)
			v.push_back(servers[i]->lastKnownInterface);
		return v;
	}
	virtual int size() { return servers.size(); }
	virtual vector<UID> const& getServerIDs() { return serverIDs; }
	virtual void addDataInFlightToTeam( int64_t delta ) {
		for(int i=0; i<servers.size(); i++)
			servers[i]->dataInFlightToServer += delta;
	}
	virtual int64_t getDataInFlightToTeam() {
		int64_t dataInFlight = 0.0;
		for(int i=0; i<servers.size(); i++)
			dataInFlight += servers[i]->dataInFlightToServer;
		return dataInFlight;
	}

	virtual int64_t getLoadBytes( bool includeInFlight = true, double inflightPenalty = 1.0 ) {
		int64_t physicalBytes = getLoadAverage();
		double minFreeSpaceRatio = getMinFreeSpaceRatio(includeInFlight);
		int64_t inFlightBytes = includeInFlight ? getDataInFlightToTeam() / servers.size() : 0;
		double freeSpaceMultiplier = SERVER_KNOBS->FREE_SPACE_RATIO_CUTOFF / ( std::max( std::min( SERVER_KNOBS->FREE_SPACE_RATIO_CUTOFF, minFreeSpaceRatio ), 0.000001 ) );

		if(freeSpaceMultiplier > 1 && g_random->random01() < 0.001)
			TraceEvent(SevWarn, "DiskNearCapacity").detail("FreeSpaceRatio", minFreeSpaceRatio);

		return (physicalBytes + (inflightPenalty*inFlightBytes)) * freeSpaceMultiplier;
	}

	virtual int64_t getMinFreeSpace( bool includeInFlight = true ) {
		int64_t minFreeSpace = std::numeric_limits<int64_t>::max();
		for(int i=0; i<servers.size(); i++) {
			if( servers[i]->serverMetrics.present() ) {
				auto& replyValue = servers[i]->serverMetrics.get();

				ASSERT(replyValue.free.bytes >= 0);
				ASSERT(replyValue.capacity.bytes >= 0);

				int64_t bytesFree = replyValue.free.bytes;
				if(includeInFlight) {
					bytesFree -= servers[i]->dataInFlightToServer;
				}

				minFreeSpace = std::min(bytesFree, minFreeSpace);
			}
		}

		return minFreeSpace; // Could be negative
	}

	virtual double getMinFreeSpaceRatio( bool includeInFlight = true ) {
		double minRatio = 1.0;
		for(int i=0; i<servers.size(); i++) {
			if( servers[i]->serverMetrics.present() ) {
				auto& replyValue = servers[i]->serverMetrics.get();

				ASSERT(replyValue.free.bytes >= 0);
				ASSERT(replyValue.capacity.bytes >= 0);

				int64_t bytesFree = replyValue.free.bytes;
				if(includeInFlight) {
					bytesFree = std::max((int64_t)0, bytesFree - servers[i]->dataInFlightToServer);
				}

				if(replyValue.capacity.bytes == 0)
					minRatio = 0;
				else
					minRatio = std::min( minRatio, ((double)bytesFree) / replyValue.capacity.bytes );
			}
		}

		return minRatio;
	}

	virtual bool hasHealthyFreeSpace() {
		return getMinFreeSpaceRatio() > SERVER_KNOBS->MIN_FREE_SPACE_RATIO && getMinFreeSpace() > SERVER_KNOBS->MIN_FREE_SPACE;
	}

	virtual Future<Void> updatePhysicalMetrics() {
		return doUpdatePhysicalMetrics( this );
	}

	virtual bool isOptimal() {
		for(int i=0; i<servers.size(); i++) {
			if( servers[i]->lastKnownClass.machineClassFitness( ProcessClass::Storage ) > ProcessClass::UnsetFit ) {
				return false;
			}
		}
		return true;
	}

	virtual bool isWrongConfiguration() { return wrongConfiguration; }
	virtual void setWrongConfiguration(bool wrongConfiguration) { this->wrongConfiguration = wrongConfiguration; }
	virtual bool isHealthy() { return healthy; }
	virtual void setHealthy(bool h) { healthy = h; }
	virtual int getPriority() { return priority; }
	virtual void setPriority(int p) { priority = p; }
	virtual void addref() { ReferenceCounted<TCTeamInfo>::addref(); }
	virtual void delref() { ReferenceCounted<TCTeamInfo>::delref(); }

	virtual void addServers(const vector<UID> & servers) {
		serverIDs.reserve(servers.size());
		for (int i = 0; i < servers.size(); i++) {
			serverIDs.push_back(servers[i]);
		}
	}

private:
	// Calculate an "average" of the metrics replies that we received.  Penalize teams from which we did not receieve all replies.
	int64_t getLoadAverage() {
		int64_t bytesSum = 0;
		int added = 0;
		for(int i=0; i<servers.size(); i++)
			if( servers[i]->serverMetrics.present() ) {
				added++;
				bytesSum += servers[i]->serverMetrics.get().load.bytes;
			}

		if( added < servers.size() )
			bytesSum *= 2;

		return added == 0 ? 0 : bytesSum / added;
	}

	// Calculate the max of the metrics replies that we received.


	ACTOR Future<Void> doUpdatePhysicalMetrics( TCTeamInfo* self ) {
		std::vector<Future<Void>> updates;
		for( int i = 0; i< self->servers.size(); i++ )
			updates.push_back( updateServerMetrics( self->servers[i] ) );
		Void _ = wait( waitForAll( updates ) );
		return Void();
	}
};

struct ServerStatus {
	bool isFailed;
	bool isUndesired;
	bool isWrongConfiguration;
	LocalityData locality;
	ServerStatus() : isFailed(true), isUndesired(false), isWrongConfiguration(false) {}
	ServerStatus( bool isFailed, bool isUndesired, LocalityData const& locality ) : isFailed(isFailed), isUndesired(isUndesired), locality(locality), isWrongConfiguration(false) {}
	bool isUnhealthy() const { return isFailed || isUndesired; }
	const char* toString() const { return isFailed ? "Failed" : isUndesired ? "Undesired" : "Healthy"; }

	bool operator == (ServerStatus const& r) const { return isFailed == r.isFailed && isUndesired == r.isUndesired && isWrongConfiguration == r.isWrongConfiguration && locality.zoneId() == r.locality.zoneId(); }

	//If a process has reappeared without the storage server that was on it (isFailed == true), we don't need to exclude it
	//We also don't need to exclude processes who are in the wrong configuration (since those servers will be removed)
	bool excludeOnRecruit() { return !isFailed && !isWrongConfiguration; }
};
typedef AsyncMap<UID, ServerStatus> ServerStatusMap;

ACTOR Future<Void> waitForAllDataRemoved( Database cx, UID serverID ) {
	state Transaction tr(cx);
	loop {
		try {
			tr.setOption(FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE);
			bool canRemove = wait( canRemoveStorageServer( &tr, serverID ) );
			if (canRemove)
				return Void();

			// Wait for any change to the serverKeys for this server
			Void _ = wait( delay(SERVER_KNOBS->ALL_DATA_REMOVED_DELAY, TaskDataDistribution) );
			//Void _ = tr.waitForChanges( KeyRangeRef( serverKeysPrefixFor(serverID),
			//										 serverKeysPrefixFor(serverID).toString() + allKeys.end.toString() ) );
			tr.reset();
		} catch (Error& e) {
			Void _ = wait( tr.onError(e) );
		}
	}
}

ACTOR Future<Void> storageServerFailureTracker(
	Database cx,
	StorageServerInterface server,
	ServerStatusMap *statusMap,
	ServerStatus *status,
	PromiseStream<Void> serverFailures,
	int64_t *unhealthyServers,
	UID masterId )
{
	loop {
		bool unhealthy = statusMap->count(server.id()) && statusMap->get(server.id()).isUnhealthy();
		if(unhealthy && !status->isUnhealthy()) {
			(*unhealthyServers)--;
		}
		if(!unhealthy && status->isUnhealthy()) {
			(*unhealthyServers)++;
		}

		statusMap->set( server.id(), *status );
		if( status->isFailed )
			serverFailures.send( Void() );

		choose {
			when ( Void _ = wait( status->isFailed
				? IFailureMonitor::failureMonitor().onStateEqual( server.waitFailure.getEndpoint(), FailureStatus(false) )
				: waitFailureClient(server.waitFailure, SERVER_KNOBS->DATA_DISTRIBUTION_FAILURE_REACTION_TIME, 0, TaskDataDistribution) ) )
			{
				status->isFailed = !status->isFailed;
				TraceEvent("StatusMapChange", masterId).detail("ServerID", server.id()).detail("Status", status->toString()).
					detail("Available", IFailureMonitor::failureMonitor().getState(server.waitFailure.getEndpoint()).isAvailable());
			}
			when ( Void _ = wait( status->isUnhealthy() ? waitForAllDataRemoved(cx, server.id()) : Never() ) ) { break; }
		}
	}

	return Void();
}

// Read keyservers, return unique set of teams
ACTOR Future<Reference<InitialDataDistribution>> getInitialDataDistribution( Database cx, UID masterId, MoveKeysLock moveKeysLock ) {
	state Reference<InitialDataDistribution> result = Reference<InitialDataDistribution>(new InitialDataDistribution);
	state Key beginKey = allKeys.begin;

	state bool succeeded;

	state Transaction tr( cx );

	//Get the server list in its own try/catch block since it modifies result.  We don't want a subsequent failure causing entries to be duplicated
	loop {
		succeeded = false;
		try {
			result->mode = 1;
			tr.setOption(FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE);
			Optional<Value> mode = wait( tr.get( dataDistributionModeKey ) );
			if (mode.present()) {
				BinaryReader rd( mode.get(), Unversioned() );
				rd >> result->mode;
			}
			if(!result->mode)
				return result;


			state Future<vector<ProcessData>> workers = getWorkers(&tr);
			state Future<Standalone<RangeResultRef>> serverList = tr.getRange( serverListKeys, CLIENT_KNOBS->TOO_MANY );
			Void _ = wait( success(workers) && success(serverList) );
			ASSERT( !serverList.get().more && serverList.get().size() < CLIENT_KNOBS->TOO_MANY );

			std::map<Optional<Standalone<StringRef>>, ProcessData> id_data;
			for( int i = 0; i < workers.get().size(); i++ )
				id_data[workers.get()[i].locality.processId()] = workers.get()[i];

			succeeded = true;

			for( int i = 0; i < serverList.get().size(); i++ ) {
				auto ssi = decodeServerListValue( serverList.get()[i].value );
				result->allServers.push_back( std::make_pair(ssi, id_data[ssi.locality.processId()].processClass) );
			}

			break;
		}
		catch(Error &e) {
			Void _ = wait( tr.onError(e) );

			ASSERT(!succeeded); //We shouldn't be retrying if we have already started modifying result in this loop
			TraceEvent("getInitialTeamsRetry", masterId);
		}
	}

	//If keyServers is too large to read in a single transaction, then we will have to break this process up into multiple transactions.
	//In that case, each iteration should begin where the previous left off
	while(beginKey < allKeys.end) {
		TEST(beginKey > allKeys.begin); //Multi-transactional getInitialDataDistribution
		loop {
			succeeded = false;
			try {
				tr.setOption(FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE);
				Void _ = wait(checkMoveKeysLockReadOnly(&tr, moveKeysLock));
				Standalone<RangeResultRef> keyServers = wait(krmGetRanges(&tr, keyServersPrefix, KeyRangeRef(beginKey, allKeys.end), SERVER_KNOBS->MOVE_KEYS_KRM_LIMIT, SERVER_KNOBS->MOVE_KEYS_KRM_LIMIT_BYTES));
				succeeded = true;

				vector<UID> src, dest, last;

				// for each range
				for(int i = 0; i < keyServers.size() - 1; i++) {
					KeyRangeRef keys( keyServers[i].key, keyServers[i+1].key );
					decodeKeyServersValue( keyServers[i].value, src, dest );
					std::pair<vector<UID>,vector<UID>> teams;
					for(int j=0; j<src.size(); j++)
						teams.first.push_back(src[j]);
					for(int j=0; j<dest.size(); j++)
						teams.second.push_back(dest[j]);
					result->shards.push_back( keyRangeWith(keys, teams) );
					result->teams.insert( teams.first );
					if (dest.size())
						result->teams.insert( teams.second );
				}

				ASSERT(keyServers.size() > 0);
				beginKey = keyServers.end()[-1].key;
				break;
			} catch (Error& e) {
				Void _ = wait( tr.onError(e) );

				ASSERT(!succeeded); //We shouldn't be retrying if we have already started modifying result in this loop
				TraceEvent("getInitialTeamsKeyServersRetry", masterId);
			}
		}

		tr.reset();
	}

	// a dummy shard at the end with no keys or servers makes life easier for trackInitialShards()
	result->shards.push_back( keyRangeWith(KeyRangeRef(allKeys.end,allKeys.end), std::pair<vector<UID>, vector<UID>>()) );

	return result;
}

Future<Void> storageServerTracker(
	struct DDTeamCollection* const& self,
	Database const& cx,
	TCServerInfo* const& server,
	ServerStatusMap* const& statusMap,
	MoveKeysLock const& lock,
	UID const& masterId,
	std::map<UID, Reference<TCServerInfo>>* const& other_servers,
	PromiseStream< std::pair<UID, Optional<StorageServerInterface>> > const& changes,
	PromiseStream<Void> const& serverFailures,
	Promise<Void> const& errorOut);

Future<Void> teamTracker( struct DDTeamCollection* const& self, Reference<IDataDistributionTeam> const& team );

struct DDTeamCollection {
	enum { REQUESTING_WORKER = 0, GETTING_WORKER = 1, GETTING_STORAGE = 2 };

	PromiseStream<Future<Void>> addActor;
	Database cx;
	UID masterId;
	DatabaseConfiguration configuration;

	bool doBuildTeams;
	Future<Void> teamBuilder;
	AsyncTrigger restartTeamBuilder;

	MoveKeysLock lock;
	PromiseStream<RelocateShard> output;
	vector<UID> allServers;
	ServerStatusMap server_status;
	int64_t unhealthyServers;
	std::map<UID, Reference<TCServerInfo>> server_info;
	vector<Reference<TCTeamInfo>> teams;
	Reference<ShardsAffectedByTeamFailure> shardsAffectedByTeamFailure;
	PromiseStream<UID> removedServers;
	std::set<UID> recruitingIds; // The IDs of the SS which are being recruited
	std::set<NetworkAddress> recruitingLocalities;
	PromiseStream< std::pair<UID, Optional<StorageServerInterface>> > serverChanges;
	PromiseStream<Void> serverFailures;
	Future<Void> initialFailureReactionDelay;
	Future<Void> initializationDoneActor;
	Promise<Void> serverTrackerErrorOut;
	AsyncVar<int> recruitingStream;
	Debouncer restartRecruiting;

	int healthyTeamCount;
	Reference<AsyncVar<bool>> zeroHealthyTeams;

	int optimalTeamCount;
	AsyncVar<bool> zeroOptimalTeams;

	AsyncMap< AddressExclusion, bool > excludedServers;  // true if an address is in the excluded list in the database.  Updated asynchronously (eventually)

	std::vector<Optional<Key>> includedDCs;
	Optional<std::vector<Optional<Key>>> otherTrackedDCs;
	DDTeamCollection(
		Database const& cx,
		UID masterId,
		MoveKeysLock const& lock,
		PromiseStream<RelocateShard> const& output,
		Reference<ShardsAffectedByTeamFailure> const& shardsAffectedByTeamFailure,
		DatabaseConfiguration configuration,
		std::vector<Optional<Key>> includedDCs,
		Optional<std::vector<Optional<Key>>> otherTrackedDCs,
		PromiseStream< std::pair<UID, Optional<StorageServerInterface>> > const& serverChanges,
		Future<Void> readyToStart, Reference<AsyncVar<bool>> zeroHealthyTeams )
		:cx(cx), masterId(masterId), lock(lock), output(output), shardsAffectedByTeamFailure(shardsAffectedByTeamFailure), doBuildTeams( true ), teamBuilder( Void() ),
		 configuration(configuration), serverChanges(serverChanges),
		 initialFailureReactionDelay( delay( BUGGIFY ? 0 : SERVER_KNOBS->INITIAL_FAILURE_REACTION_DELAY, TaskDataDistribution  ) ), healthyTeamCount( 0 ),
		 initializationDoneActor(logOnCompletion(readyToStart && initialFailureReactionDelay, this)), optimalTeamCount( 0 ), recruitingStream(0), restartRecruiting( SERVER_KNOBS->DEBOUNCE_RECRUITING_DELAY ),
		 unhealthyServers(0), includedDCs(includedDCs), otherTrackedDCs(otherTrackedDCs), zeroHealthyTeams(zeroHealthyTeams), zeroOptimalTeams(true)
	{
		TraceEvent("DDTrackerStarting", masterId)
			.detail( "State", "Inactive" )
			.trackLatest( format("%s/DDTrackerStarting", printable(cx->dbName).c_str() ).c_str() );
	}

	~DDTeamCollection() {
		// The following kills a reference cycle between the teamTracker actor and the TCTeamInfo that both holds and is held by the actor
		// It also ensures that the trackers are done fiddling with healthyTeamCount before we free this
		for(int i=0; i < teams.size(); i++) {
			teams[i]->tracker.cancel();
		}
		// The following makes sure that, even if a reference to a team is held in the DD Queue, the tracker will be stopped
		//  before the server_status map to which it has a pointer, is destroyed.
		for(auto it = server_info.begin(); it != server_info.end(); ++it) {
			it->second->tracker.cancel();
		}

		teamBuilder.cancel();
	}

	ACTOR Future<Void> logOnCompletion( Future<Void> signal, DDTeamCollection *self ) {
		Void _ = wait(signal);
		Void _ = wait(delay(SERVER_KNOBS->LOG_ON_COMPLETION_DELAY, TaskDataDistribution));

		TraceEvent("DDTrackerStarting", self->masterId)
			.detail( "State", "Active" )
			.trackLatest( format("%s/DDTrackerStarting", printable(self->cx->dbName).c_str() ).c_str() );

		return Void();
	}

	ACTOR Future<Void> checkBuildTeams( DDTeamCollection* self ) {
		state Promise<Void> restart;

		while( !self->teamBuilder.isReady() )
			Void _ = wait( self->teamBuilder );

		if( self->doBuildTeams ) {
			self->doBuildTeams = false;
			try {
				loop {
					Promise<Void> oldRestart = restart;
					restart = Promise<Void>();
					self->teamBuilder = self->buildTeams( self ) || restart.getFuture();
					oldRestart.send( Void() );
					choose {
						when( Void _ = wait( self->teamBuilder ) ) { break; }
						when( Void _ = wait( self->restartTeamBuilder.onTrigger() ) ) {}
					}
				}
			}
			catch(Error &e) {
				if(!restart.isSet()) {
					restart.send(Void());
				}
				throw;
			}
		}

		return Void();
	}

	// SOMEDAY: Make bestTeam better about deciding to leave a shard where it is (e.g. in PRIORITY_TEAM_HEALTHY case)
	//		    use keys, src, dest, metrics, priority, system load, etc.. to decide...
	ACTOR Future<Void> getTeam( DDTeamCollection* self, GetTeamRequest req ) {
		try {
			Void _ = wait( self->checkBuildTeams( self ) );

			// Select the best team
			// Currently the metric is minimum used disk space (adjusted for data in flight)
			// Only healthy teams may be selected. The team has to be healthy at the moment we update
			//   shardsAffectedByTeamFailure or we could be dropping a shard on the floor (since team
			//   tracking is "edge triggered")
			// SOMEDAY: Account for capacity, load (when shardMetrics load is high)

			if( !self->teams.size() ) {
				req.reply.send( Optional<Reference<IDataDistributionTeam>>() );
				return Void();
			}

			int64_t bestLoadBytes = 0;
			Optional<Reference<IDataDistributionTeam>> bestOption;
			std::vector<std::pair<int, Reference<IDataDistributionTeam>>> randomTeams;
			std::set< UID > sources;

			if( !req.wantsNewServers ) {
				std::vector<Reference<IDataDistributionTeam>> similarTeams;
				bool foundExact = false;

				for( int i = 0; i < req.sources.size(); i++ )
					sources.insert( req.sources[i] );

				for( int i = 0; i < req.sources.size(); i++ ) {
					if( !self->server_info.count( req.sources[i] ) ) {
						TEST( true ); // GetSimilarTeams source server now unknown
					}
					else {
						auto& teamList = self->server_info[ req.sources[i] ]->teams;
						for( int j = 0; j < teamList.size(); j++ ) {
							if( teamList[j]->isHealthy() && (!req.preferLowerUtilization || teamList[j]->hasHealthyFreeSpace())) {
								int sharedMembers = 0;
								for( int k = 0; k < teamList[j]->serverIDs.size(); k++ )
									if( sources.count( teamList[j]->serverIDs[k] ) )
										sharedMembers++;

								if( !foundExact && sharedMembers == teamList[j]->serverIDs.size() ) {
									foundExact = true;
									bestOption = Optional<Reference<IDataDistributionTeam>>();
									similarTeams.clear();
								}

								if( (sharedMembers == teamList[j]->serverIDs.size()) || (!foundExact && req.wantsTrueBest) ) {
									int64_t loadBytes = SOME_SHARED * teamList[j]->getLoadBytes(true, req.inflightPenalty);
									if( !bestOption.present() || ( req.preferLowerUtilization && loadBytes < bestLoadBytes ) || ( !req.preferLowerUtilization && loadBytes > bestLoadBytes ) ) {
										bestLoadBytes = loadBytes;
										bestOption = teamList[j];
									}
								}
								else if( !req.wantsTrueBest && !foundExact )
									similarTeams.push_back( teamList[j] );
							}
						}
					}
				}

				if( foundExact || (req.wantsTrueBest && bestOption.present() ) ) {
					TraceEvent("getTeam").detail("wantsVariety", req.wantsNewServers).detail("bestOption", bestOption.get()->getDesc());
					ASSERT( bestOption.present() );
					req.reply.send( bestOption );
					return Void();
				}

				if( !req.wantsTrueBest ) {
					while( similarTeams.size() && randomTeams.size() < SERVER_KNOBS->BEST_TEAM_OPTION_COUNT ) {
						int randomTeam = g_random->randomInt( 0, similarTeams.size() );
						randomTeams.push_back( std::make_pair( SOME_SHARED, similarTeams[randomTeam] ) );
						std::swap( similarTeams[randomTeam], similarTeams.back() );
						similarTeams.pop_back();
					}
				}
			}

			if( req.wantsTrueBest ) {
				ASSERT( !bestOption.present() );
				for( int i = 0; i < self->teams.size(); i++ ) {
					if( self->teams[i]->isHealthy() && (!req.preferLowerUtilization || self->teams[i]->hasHealthyFreeSpace()) ) {
						int64_t loadBytes = NONE_SHARED * self->teams[i]->getLoadBytes(true, req.inflightPenalty);
						if( !bestOption.present() || ( req.preferLowerUtilization && loadBytes < bestLoadBytes ) || ( !req.preferLowerUtilization && loadBytes > bestLoadBytes ) ) {
							bestLoadBytes = loadBytes;
							bestOption = self->teams[i];
						}
					}
				}
			}
			else {
				int nTries = 0;
				while( randomTeams.size() < SERVER_KNOBS->BEST_TEAM_OPTION_COUNT && nTries < SERVER_KNOBS->BEST_TEAM_MAX_TEAM_TRIES ) {
					Reference<IDataDistributionTeam> dest = g_random->randomChoice(self->teams);

					bool ok = dest->isHealthy() && (!req.preferLowerUtilization || dest->hasHealthyFreeSpace());
					for(int i=0; ok && i<randomTeams.size(); i++)
						if (randomTeams[i].second->getServerIDs() == dest->getServerIDs())
							ok = false;

					if (ok)
						randomTeams.push_back( std::make_pair( NONE_SHARED, dest ) );
					else
						nTries++;
				}

				for( int i = 0; i < randomTeams.size(); i++ ) {
					int64_t loadBytes = randomTeams[i].first * randomTeams[i].second->getLoadBytes(true, req.inflightPenalty);
					if( !bestOption.present() || ( req.preferLowerUtilization && loadBytes < bestLoadBytes ) || ( !req.preferLowerUtilization && loadBytes > bestLoadBytes ) ) {
						bestLoadBytes = loadBytes;
						bestOption = randomTeams[i].second;
					}
				}
			}

			if(!bestOption.present() && self->zeroHealthyTeams->get()) {
				//Attempt to find the unhealthy source server team and return it
				std::set<UID> completeSources;
				for( int i = 0; i < req.completeSources.size(); i++ ) {
					completeSources.insert( req.completeSources[i] );
				}

				int bestSize = 0;
				for( int i = 0; i < req.sources.size(); i++ ) {
					if( self->server_info.count( req.sources[i] ) ) {
						auto& teamList = self->server_info[ req.sources[i] ]->teams;
						for( int j = 0; j < teamList.size(); j++ ) {
							bool found = true;
							for( int k = 0; k < teamList[j]->serverIDs.size(); k++ ) {
								if( !completeSources.count( teamList[j]->serverIDs[k] ) ) {
									found = false;
									break;
								}
							}
							if(found && teamList[j]->serverIDs.size() > bestSize) {
								bestOption = teamList[j];
								bestSize = teamList[j]->serverIDs.size();
							}
						}
						break;
					}
				}
			}

			req.reply.send( bestOption );
			return Void();
		} catch( Error &e ) {
			if( e.code() != error_code_actor_cancelled)
				req.reply.sendError( e );
			throw;
		}
	}

	int64_t getDebugTotalDataInFlight() {
		int64_t total = 0;
		for(auto itr = server_info.begin(); itr != server_info.end(); ++itr)
			total += itr->second->dataInFlightToServer;
		return total;
	}

	void addSubsetOfEmergencyTeams() {
		for( int i = 0; i < teams.size(); i++ ) {
			if( teams[i]->servers.size() > configuration.storageTeamSize ) {
				auto& serverIds = teams[i]->getServerIDs();
				bool foundTeam = false;
				for( int j = 0; j < std::max( 1, (int)(serverIds.size() - configuration.storageTeamSize + 1) ) && !foundTeam; j++ ) {
					auto& serverTeams = server_info[serverIds[j]]->teams;
					for( int k = 0; k < serverTeams.size(); k++ ) {
						auto &testTeam = serverTeams[k]->getServerIDs();
						bool allInTeam = true;
						for( int l = 0; l < testTeam.size(); l++ ) {
							if( std::find( serverIds.begin(), serverIds.end(), testTeam[l] ) == serverIds.end() ) {
								allInTeam = false;
								break;
							}
						}
						if( allInTeam ) {
							foundTeam = true;
							break;
						}
					}
				}
				if( !foundTeam ) {
					addTeam(serverIds.begin(), serverIds.begin() + configuration.storageTeamSize );
				}
			}
		}
	}

	void init( InitialDataDistribution const& initTeams ) {
		// SOMEDAY: If some servers have teams and not others (or some servers have more data than others) and there is an address/locality collision, should
		// we preferentially mark the least used server as undesirable?
		for (auto i = initTeams.allServers.begin(); i != initTeams.allServers.end(); ++i) {
			if (shouldHandleServer(i->first)) {
				addServer(i->first, i->second, serverTrackerErrorOut);
			}
		}

		for(auto t = initTeams.teams.begin(); t != initTeams.teams.end(); ++t) {
			addTeam(t->begin(), t->end() );
		}

		addSubsetOfEmergencyTeams();
	}

	void evaluateTeamQuality() {
		int teamCount = teams.size(), serverCount = allServers.size();
		double teamsPerServer = (double)teamCount * configuration.storageTeamSize / serverCount;

		ASSERT( serverCount == server_info.size() );

		int minTeams = 100000, maxTeams = 0;
		double varTeams = 0;

		std::map<Optional<Standalone<StringRef>>, int> machineTeams;
		for(auto s = server_info.begin(); s != server_info.end(); ++s) {
			if(!server_status.get(s->first).isUndesired) {
				int stc = s->second->teams.size();
				minTeams = std::min(minTeams, stc);
				maxTeams = std::max(maxTeams, stc);
				varTeams += (stc - teamsPerServer)*(stc - teamsPerServer);
				machineTeams[s->second->lastKnownInterface.locality.zoneId()] += stc;
			}
		}
		varTeams /= teamsPerServer*teamsPerServer;

		int minMachineTeams = 100000, maxMachineTeams = 0;
		for( auto m = machineTeams.begin(); m != machineTeams.end(); ++m ) {
			minMachineTeams = std::min( minMachineTeams, m->second );
			maxMachineTeams = std::max( maxMachineTeams, m->second );
		}

		TraceEvent(
			minTeams>0 ? SevInfo : SevWarn,
			"DataDistributionTeamQuality", masterId)
			.detail("Servers", serverCount)
			.detail("Teams", teamCount)
			.detail("TeamsPerServer", teamsPerServer)
			.detail("Variance", varTeams/serverCount)
			.detail("ServerMinTeams", minTeams)
			.detail("ServerMaxTeams", maxTeams)
			.detail("MachineMinTeams", minMachineTeams)
			.detail("MachineMaxTeams", maxMachineTeams);
	}

	bool teamExists( vector<UID> &team ) {
		bool exists = false;
		for (int i=0;i<teams.size();i++){
			if (teams[i]->getServerIDs() == team) {
				exists = true;
				break;
			}
		}
		return exists;
	}

	void addTeam( std::set<UID> const& team ) {
		addTeam(team.begin(), team.end());
	}

	template<class InputIt>
	void addTeam( InputIt begin, InputIt end) {
		vector< Reference<TCServerInfo> > newTeamServers;
		for (auto i = begin; i != end; ++i) {
			if (server_info.find(*i) != server_info.end()) {
				newTeamServers.push_back(server_info[*i]);
			}
		}

		if(newTeamServers.empty()) {
			return;
		}
		Reference<TCTeamInfo> teamInfo( new TCTeamInfo( newTeamServers ) );
		TraceEvent("TeamCreation", masterId).detail("Team", teamInfo->getDesc());
		teamInfo->tracker = teamTracker( this, teamInfo );
		teams.push_back( teamInfo );
		for (int i=0;i<newTeamServers.size();i++) {
			server_info[ newTeamServers[i]->id ]->teams.push_back( teamInfo );
		}
	}

	ACTOR Future<Void> addAllTeams( DDTeamCollection *self, int location, vector<LocalityEntry>* history, Reference<LocalityMap<UID>> processes, vector<std::vector<UID>>* output, int teamLimit, int* addedTeams ) {
		Void _ = wait( yield( TaskDataDistributionLaunch ) );

		// Add team, if valid
		if(history->size() == self->configuration.storageTeamSize) {
			auto valid = self->configuration.storagePolicy->validate(*history, processes);
			if(!valid) {
				return Void();
			}
			std::vector<UID> team;
			for(auto it = history->begin(); it != history->end(); it++) {
				team.push_back(*processes->getObject(*it));
			}

			if( !self->teamExists(team) && *addedTeams < teamLimit ) {
				output->push_back(team);
				(*addedTeams)++;
			}
			return Void();
		}

		//loop through remaining potential team members, add one and recursively call function
		for(; location < processes->size(); location++) {
			history->push_back(processes->getEntry(location));
			state int depth = history->size();
			Void _ = wait( self->addAllTeams( self, location + 1, history, processes, output, teamLimit, addedTeams ) );
			ASSERT( history->size() == depth); // the "stack" should be unchanged by this call
			history->pop_back();
			if(*addedTeams > teamLimit)
				break;
		}

		return Void();
	}

	ACTOR Future<int> addAllTeams( DDTeamCollection *self, vector<UID> input, vector<std::vector<UID>>* output, int teamLimit ) {
		state int addedTeams = 0;
		state vector<LocalityEntry> history;
		state Reference<LocalityMap<UID>> processes(new LocalityMap<UID>());
		for(auto it = input.begin(); it != input.end(); it++) {
			if(self->server_info[*it]) {
				processes->add(self->server_info[*it]->lastKnownInterface.locality, &*it);
			}
		}
		Void _ = wait( self->addAllTeams( self, 0, &history, processes, output, teamLimit, &addedTeams ) );
		return addedTeams;
	}

	int addTeamsBestOf( int teamsToBuild ) {
		int addedTeams = 0;

		LocalityMap<UID> totalServers;

		for(auto i = server_info.begin(); i != server_info.end(); ++i) {
			if (!server_status.get(i->first).isUndesired) {
				auto& id = i->first;
				auto& locality = i->second->lastKnownInterface.locality;
				totalServers.add(locality, &id);
			}
		}

		if(totalServers.size() < configuration.storageTeamSize ) {
			TraceEvent(SevWarn, "DataDistributionBuildTeams", masterId).detail("Reason","Not enough servers for a team").detail("Servers",totalServers.size()).detail("teamSize", configuration.storageTeamSize);
			return addedTeams;
		}

		int loopCount = 0;
		// add teams
		while( addedTeams < teamsToBuild ) {
			std::vector<LocalityEntry> leastUsedServers;
			int minTeamCount = CLIENT_KNOBS->TOO_MANY;
			for(int i = 0; i < totalServers.size(); i++) {
				LocalityEntry process = totalServers.getEntry(i);
				UID id = *totalServers.getObject(process);
				int teamCount = server_info[id]->teams.size();
				if(teamCount < minTeamCount) {
					leastUsedServers.clear();
					minTeamCount = teamCount;
				}
				if(teamCount <= minTeamCount) {
					leastUsedServers.push_back(process);
				}
			}

			std::vector<UID*> team;
			std::vector<LocalityEntry> forcedAttributes;

			if (leastUsedServers.size()) {
				forcedAttributes.push_back(g_random->randomChoice(leastUsedServers));
			}

			std::vector<UID*> bestTeam;
			int bestScore = CLIENT_KNOBS->TOO_MANY;

			int maxAttempts = SERVER_KNOBS->BEST_OF_AMT;
			for( int i = 0; i < maxAttempts && i < 100; i++) {
				team.clear();
				auto success = totalServers.selectReplicas(configuration.storagePolicy, forcedAttributes, team);
				if(!success) {
					break;
				}

				if(forcedAttributes.size() > 0) {
					team.push_back((UID*)totalServers.getObject(forcedAttributes[0]));
				}
				if( team.size() != configuration.storageTeamSize) {
					maxAttempts += 1;
				}

				int score = 0;
				for(auto process = team.begin(); process != team.end(); process++) {
					score += server_info[**process]->teams.size();
				}

				if(score < bestScore) {
					bestTeam = team;
					bestScore = score;
				}
			}

			if( bestTeam.size() == configuration.storageTeamSize) {
				vector<UID> processIDs;

				for (auto process = bestTeam.begin(); process < bestTeam.end(); process++) {
					processIDs.push_back(**process);
				}

				std::sort(processIDs.begin(), processIDs.end());

				if( !teamExists( processIDs ) ) {
					addTeam(processIDs.begin(), processIDs.end());
					addedTeams++;
				}
			}
			else {
				TraceEvent(SevWarn, "DataDistributionBuildTeams", masterId).detail("Reason","Unable to make desiredTeams");
				break;
			}
			if(++loopCount > 2*teamsToBuild*(configuration.storageTeamSize+1) ) {
				break;
			}
		}
		return addedTeams;
	}

	// Use the current set of known processes (from server_info) to compute an optimized set of storage server teams.
	// The following are guarantees of the process:
	//   - Each newly-built team will meet the replication policy
	//   - All newly-built teams will have exactly teamSize machines
	//
	// buildTeams() only ever adds teams to the list of teams. Teams are only removed from the list when all data has been removed.
	//
	// buildTeams will not count teams larger than teamSize against the desired teams.
	ACTOR Future<Void> buildTeams( DDTeamCollection* self ) {
		state int desiredTeams;
		int serverCount = 0;
		int uniqueDataCenters = 0;
		int uniqueMachines = 0;
		std::set<Optional<Standalone<StringRef>>> machines;

		for(auto i = self->server_info.begin(); i != self->server_info.end(); ++i) {
			if (!self->server_status.get(i->first).isUndesired) {
				++serverCount;
				LocalityData& serverLocation = i->second->lastKnownInterface.locality;
				machines.insert( serverLocation.zoneId() );
			}
		}
		uniqueMachines = machines.size();

		// If there are too few machines to even build teams or there are too few represented datacenters, build no new teams
		if( uniqueMachines >= self->configuration.storageTeamSize ) {
			desiredTeams = SERVER_KNOBS->DESIRED_TEAMS_PER_SERVER*serverCount;

			// Count only properly sized teams against the desired number of teams. This is to prevent "emergency" merged teams (see MoveKeys)
			//  from overwhelming the team count (since we really did not want that team in the first place). These larger teams will not be
			//  returned from getRandomTeam() (as used by bestTeam to find a new home for a shard).
			// Also exclude teams who have members in the wrong configuration, since we don't want these teams either
			int teamCount = 0;
			for(int i = 0; i < self->teams.size(); i++) {
				if( self->teams[i]->getServerIDs().size() == self->configuration.storageTeamSize && !self->teams[i]->isWrongConfiguration() ) {
					teamCount++;
				}
			}

			TraceEvent("BuildTeamsBegin", self->masterId).detail("DesiredTeams", desiredTeams).detail("UniqueMachines", uniqueMachines)
				.detail("TeamSize", self->configuration.storageTeamSize).detail("Servers", serverCount)
				.detail("CurrentTrackedTeams", self->teams.size()).detail("TeamCount", teamCount);

			if( desiredTeams > teamCount ) {
				std::set<UID> desiredServerSet;
				for(auto i = self->server_info.begin(); i != self->server_info.end(); ++i)
					if (!self->server_status.get(i->first).isUndesired)
						desiredServerSet.insert(i->second->id);

				vector<UID> desiredServerVector( desiredServerSet.begin(), desiredServerSet.end() );

				state int teamsToBuild = desiredTeams - teamCount;

				state vector<std::vector<UID>> builtTeams;

				if( self->configuration.storageTeamSize > 3) {
					int addedTeams = self->addTeamsBestOf( teamsToBuild );
					TraceEvent("AddTeamsBestOf", self->masterId).detail("CurrentTeams", self->teams.size()).detail("AddedTeams", addedTeams);
				} else {
					int addedTeams = wait( self->addAllTeams( self, desiredServerVector, &builtTeams, teamsToBuild ) );

					if( addedTeams < teamsToBuild ) {
						for( int i = 0; i < builtTeams.size(); i++ ) {
							std::sort(builtTeams[i].begin(), builtTeams[i].end());
							self->addTeam( builtTeams[i].begin(), builtTeams[i].end() );
						}
						TraceEvent("AddAllTeams", self->masterId).detail("CurrentTeams", self->teams.size()).detail("AddedTeams", builtTeams.size());
					}
					else {
						int addedTeams = self->addTeamsBestOf( teamsToBuild );
						TraceEvent("AddTeamsBestOf", self->masterId).detail("CurrentTeams", self->teams.size()).detail("AddedTeams", addedTeams);
					}
				}
			}
		}

		self->evaluateTeamQuality();

		//Building teams can cause servers to become undesired, which can make teams unhealthy.
		//Let all of these changes get worked out before responding to the get team request
		Void _ = wait( delay(0, TaskDataDistributionLaunch) );

		return Void();
	}

	void noHealthyTeams() {
		std::set<UID> desiredServerSet;
		std::string desc;
		for(auto i = server_info.begin(); i != server_info.end(); ++i) {
			ASSERT(i->first == i->second->id);
			if (!server_status.get(i->first).isFailed) {
				desiredServerSet.insert(i->first);
				desc += i->first.shortString() + " (" + i->second->lastKnownInterface.toString() + "), ";
			}
		}
		vector<UID> desiredServerVector( desiredServerSet.begin(), desiredServerSet.end() );

		TraceEvent(SevWarn, "NoHealthyTeams", masterId)
			.detail("CurrentTeamCount", teams.size())
			.detail("ServerCount", server_info.size())
			.detail("NonFailedServerCount", desiredServerVector.size());
	}

	void countHealthyTeams() {
		int healthy = 0;
		for(auto it = teams.begin(); it != teams.end(); it++) {
			if( (*it)->isHealthy() ) {
				healthy++;
			}
		}
		TraceEvent(healthy == healthyTeamCount ? SevInfo : SevWarnAlways, "HealthyTeamCheck", masterId)
			.detail("ValidatedCount", healthy)
			.detail("ProvidedCount", healthyTeamCount);
	}

	bool shouldHandleServer(const StorageServerInterface &newServer) {
		return (includedDCs.empty() || std::find(includedDCs.begin(), includedDCs.end(), newServer.locality.dcId()) != includedDCs.end() || (otherTrackedDCs.present() && std::find(otherTrackedDCs.get().begin(), otherTrackedDCs.get().end(), newServer.locality.dcId()) == otherTrackedDCs.get().end()));
	}

	void addServer( StorageServerInterface newServer, ProcessClass processClass, Promise<Void> errorOut ) {
		if (!shouldHandleServer(newServer)) {
			return;
		}
		allServers.push_back( newServer.id() );

		TraceEvent("AddedStorageServer", masterId).detail("ServerID", newServer.id()).detail("ProcessClass", processClass.toString()).detail("WaitFailureToken", newServer.waitFailure.getEndpoint().token).detail("address", newServer.waitFailure.getEndpoint().address);
		auto &r = server_info[newServer.id()] = Reference<TCServerInfo>( new TCServerInfo( newServer, processClass ) );
		r->tracker = storageServerTracker( this, cx, r.getPtr(), &server_status, lock, masterId, &server_info, serverChanges, serverFailures, errorOut );
		restartTeamBuilder.trigger();
	}

	void removeServer( UID removedServer ) {
		TraceEvent("RemovedStorageServer", masterId).detail("ServerID", removedServer);
		// ASSERT( !shardsAffectedByTeamFailure->getServersForTeam( t ) for all t in teams that contain removedServer )

		// Find all servers with which the removedServer shares teams
		std::set<UID> serversWithAjoiningTeams;
		auto& sharedTeams = server_info[ removedServer ]->teams;
		for( int i = 0; i < sharedTeams.size(); i++ ) {
			auto& teamIds = sharedTeams[i]->getServerIDs();
			serversWithAjoiningTeams.insert( teamIds.begin(), teamIds.end() );
		}
		serversWithAjoiningTeams.erase( removedServer );

		// For each server in a team with the removedServer, erase shared teams from the list of teams in that other server
		for( auto it = serversWithAjoiningTeams.begin(); it != serversWithAjoiningTeams.end(); ++it ) {
			auto& teams = server_info[ *it ]->teams;
			for( int t = 0; t < teams.size(); t++ ) {
				auto& serverIds = teams[t]->getServerIDs();
				if ( std::count( serverIds.begin(), serverIds.end(), removedServer ) ) {
					teams[t--] = teams.back();
					teams.pop_back();
				}
			}
		}

		// remove removedServer from allServers, server_info
		for(int s=0; s<allServers.size(); s++) {
			if (allServers[s] == removedServer) {
				allServers[s--] = allServers.back();
				allServers.pop_back();
			}
		}
		server_info.erase( removedServer );

		// remove all teams that contain removedServer
		// SOMEDAY: can we avoid walking through all teams, since we have an index of teams in which removedServer participated
		for(int t=0; t<teams.size(); t++) {
			if ( std::count( teams[t]->getServerIDs().begin(), teams[t]->getServerIDs().end(), removedServer ) ) {
				teams[t]->tracker.cancel();
				teams[t--] = teams.back();
				teams.pop_back();
			}
		}
		doBuildTeams = true;
		restartTeamBuilder.trigger();

		TraceEvent("DataDistributionTeamCollectionUpdate", masterId)
			.detail("Teams", teams.size())
			.detail("Servers", allServers.size());
	}
};

// Track a team and issue RelocateShards when the level of degradation changes
ACTOR Future<Void> teamTracker( DDTeamCollection *self, Reference<IDataDistributionTeam> team) {
	state int lastServersLeft = team->getServerIDs().size();
	state bool lastAnyUndesired = false;
	state bool wrongSize = team->getServerIDs().size() != self->configuration.storageTeamSize;
	state bool lastReady = self->initialFailureReactionDelay.isReady();
	state bool lastHealthy = team->isHealthy();
	state bool lastOptimal = team->isOptimal() && lastHealthy;
	state bool lastWrongConfiguration = team->isWrongConfiguration();

	if(lastHealthy) {
		self->healthyTeamCount++;
		self->zeroHealthyTeams->set(false);
	}

	if(lastOptimal) {
		self->optimalTeamCount++;
		self->zeroOptimalTeams.set(false);
	}

	state bool lastZeroHealthy = self->zeroHealthyTeams->get();

	TraceEvent("TeamTrackerStarting", self->masterId).detail("Reason", "Initial wait complete (sc)").detail("Team", team->getDesc());

	try {
		loop {
			TraceEvent("TeamHealthChangeDetected", self->masterId).detail("isReady", self->initialFailureReactionDelay.isReady() );
			// Check if the number of degraded machines has changed
			state vector<Future<Void>> change;
			auto servers = team->getServerIDs();
			bool anyUndesired = false;
			bool anyWrongConfiguration = false;
			Reference<LocalityGroup> teamLocality(new LocalityGroup());

			for(auto s = servers.begin(); s != servers.end(); ++s) {
				change.push_back( self->server_status.onChange( *s ) );
				auto& status = self->server_status.get(*s);
				if (!status.isFailed)
					teamLocality->add( status.locality );
				if (status.isUndesired)
					anyUndesired = true;
				if (status.isWrongConfiguration)
					anyWrongConfiguration = true;
			}

			int serversLeft = teamLocality->size();
			bool matchesPolicy = self->configuration.storagePolicy->validate(teamLocality->getEntries(), teamLocality);

			if( !self->initialFailureReactionDelay.isReady() )
				change.push_back( self->initialFailureReactionDelay );
			change.push_back( self->zeroHealthyTeams->onChange() );

			bool recheck = (lastReady != self->initialFailureReactionDelay.isReady() || (lastZeroHealthy && !self->zeroHealthyTeams->get())) && (!matchesPolicy || anyUndesired || team->getServerIDs().size() != self->configuration.storageTeamSize);
			lastReady = self->initialFailureReactionDelay.isReady();
			lastZeroHealthy = self->zeroHealthyTeams->get();

			if( serversLeft != lastServersLeft || anyUndesired != lastAnyUndesired || anyWrongConfiguration != lastWrongConfiguration || wrongSize || recheck ) {
				TraceEvent("TeamHealthChanged", self->masterId)
					.detail("Team", team->getDesc()).detail("serversLeft", serversLeft)
					.detail("lastServersLeft", lastServersLeft).detail("ContainsUndesiredServer", anyUndesired)
					.detail("HealthyTeamsCount", self->healthyTeamCount).detail("IsWrongConfiguration", anyWrongConfiguration);

				bool healthy = matchesPolicy && !anyUndesired && team->getServerIDs().size() == self->configuration.storageTeamSize && team->getServerIDs().size() == serversLeft;
				team->setHealthy( healthy );	// Unhealthy teams won't be chosen by bestTeam

				team->setWrongConfiguration( anyWrongConfiguration );

				bool optimal = team->isOptimal() && healthy;
				if( optimal != lastOptimal ) {
					lastOptimal = optimal;
					self->optimalTeamCount += optimal ? 1 : -1;

					ASSERT( self->optimalTeamCount >= 0 );
					self->zeroOptimalTeams.set(self->optimalTeamCount == 0);
				}

				if( lastHealthy != healthy ) {
					lastHealthy = healthy;
					self->healthyTeamCount += healthy ? 1 : -1;

					ASSERT( self->healthyTeamCount >= 0 );
					self->zeroHealthyTeams->set(self->healthyTeamCount == 0);

					if( self->healthyTeamCount == 0 ) {
						TraceEvent(SevWarn, "ZeroTeamsHealthySignalling", self->masterId).detail("SignallingTeam", team->getDesc());
					}

					TraceEvent("TeamHealthDifference", self->masterId)
						.detail("LastOptimal", lastOptimal)
						.detail("LastHealthy", lastHealthy)
						.detail("Optimal", optimal)
						.detail("OptimalTeamCount", self->optimalTeamCount);
				}

				lastServersLeft = serversLeft;
				lastAnyUndesired = anyUndesired;
				lastWrongConfiguration = anyWrongConfiguration;
				wrongSize = false;

				state int lastPriority = team->getPriority();
				if( serversLeft < self->configuration.storageTeamSize ) {
					if( serversLeft == 0 )
						team->setPriority( PRIORITY_TEAM_0_LEFT );
					else if( serversLeft == 1 )
						team->setPriority( PRIORITY_TEAM_1_LEFT );
					else if( serversLeft == 2 )
						team->setPriority( PRIORITY_TEAM_2_LEFT );
					else
						team->setPriority( PRIORITY_TEAM_UNHEALTHY );
				}
				else if ( team->getServerIDs().size() != self->configuration.storageTeamSize )
					team->setPriority( PRIORITY_TEAM_UNHEALTHY );
				else if( anyUndesired )
					team->setPriority( PRIORITY_TEAM_CONTAINS_UNDESIRED_SERVER );
				else
					team->setPriority( PRIORITY_TEAM_HEALTHY );
				TraceEvent("TeamPriorityChange", self->masterId).detail("Priority", team->getPriority());

				lastZeroHealthy = self->zeroHealthyTeams->get(); //set this again in case it changed from this teams health changing
				if( self->initialFailureReactionDelay.isReady() && !self->zeroHealthyTeams->get() ) {
					vector<KeyRange> shards = self->shardsAffectedByTeamFailure->getShardsFor( team->getServerIDs() );

					for(int i=0; i<shards.size(); i++) {
						int maxPriority = team->getPriority();
						auto teams = self->shardsAffectedByTeamFailure->getTeamsFor( shards[i] );
						for( int t=0; t<teams.size(); t++) {
							ASSERT( teams[t].size() );

							if( self->server_info.count( teams[t][0] ) ) {
								auto& info = self->server_info[teams[t][0]];

								bool found = false;
								for( int i = 0; i < info->teams.size(); i++ ) {
									if( info->teams[i]->serverIDs == teams[t] ) {
										maxPriority = std::max( maxPriority, info->teams[i]->getPriority() );
										found = true;
										break;
									}
								}

								TEST(!found); // A removed team is still associated with a shard in SABTF
							} else {
								TEST(true); // A removed server is still associated with a team in SABTF
							}
						}

						if( maxPriority == team->getPriority() || lastPriority > maxPriority ) {
							RelocateShard rs;
							rs.keys = shards[i];
							rs.priority = maxPriority;

							self->output.send(rs);
							if(g_random->random01() < 0.01) {
								TraceEvent("SendRelocateToDDQx100", self->masterId)
									.detail("Team", team->getDesc())
									.detail("KeyBegin", printable(rs.keys.begin))
									.detail("KeyEnd", printable(rs.keys.end))
									.detail("Priority", rs.priority)
									.detail("TeamFailedMachines", team->getServerIDs().size()-serversLeft)
									.detail("TeamOKMachines", serversLeft);
							}
						} else {
							TraceEvent("RelocationNotSentToDDQ", self->masterId)
								.detail("Team", team->getDesc());
						}
					}
				} else {
					TraceEvent("TeamHealthNotReady", self->masterId).detail("healthyTeamCount", self->healthyTeamCount);
				}
			}

			// Wait for any of the machines to change status
			Void _ = wait( quorum( change, 1 ) );
			Void _ = wait( yield() );
		}
	} catch(Error& e) {
		if( team->isHealthy() ) {
			self->healthyTeamCount--;
			ASSERT( self->healthyTeamCount >= 0 );

			if( self->healthyTeamCount == 0 ) {
				TraceEvent(SevWarn, "ZeroTeamsHealthySignalling", self->masterId).detail("SignallingTeam", team->getDesc());
				self->zeroHealthyTeams->set(true);
			}
		}
		throw;
	}
}

ACTOR Future<Void> trackExcludedServers( DDTeamCollection *self, Database cx ) {
	loop {
		// Fetch the list of excluded servers
		state Transaction tr(cx);
		state Optional<Value> lastChangeID;
		loop {
			try {
				state Future<Standalone<RangeResultRef>> fresults = tr.getRange( excludedServersKeys, CLIENT_KNOBS->TOO_MANY );
				state Future<Optional<Value>> fchid = tr.get( excludedServersVersionKey );
				Void _ = wait( success(fresults) && success(fchid) );

				Standalone<RangeResultRef> results = fresults.get();
				lastChangeID = fchid.get();
				ASSERT( !results.more && results.size() < CLIENT_KNOBS->TOO_MANY );

				std::set<AddressExclusion> excluded;
				for(auto r = results.begin(); r != results.end(); ++r) {
					AddressExclusion addr = decodeExcludedServersKey(r->key);
					if (addr.isValid())
						excluded.insert( addr );
				}

				TraceEvent("DDExcludedServersChanged", self->masterId).detail("Rows", results.size()).detail("Exclusions", excluded.size());

				// Reset and reassign self->excludedServers based on excluded, but weonly
				// want to trigger entries that are different
				auto old = self->excludedServers.getKeys();
				for(auto& o : old)
					if (!excluded.count(o))
						self->excludedServers.set(o, false);
				for(auto& n : excluded)
					self->excludedServers.set(n, true);
				self->restartRecruiting.trigger();
				break;
			} catch (Error& e) {
				Void _ = wait( tr.onError(e) );
			}
		}

		// Wait for a change in the list of excluded servers
		loop {
			try {
				Optional<Value> nchid = wait( tr.get( excludedServersVersionKey ) );
				if (nchid != lastChangeID)
					break;

				Void _ = wait( delay( SERVER_KNOBS->SERVER_LIST_DELAY, TaskDataDistribution ) );  // FIXME: make this tr.watch( excludedServersVersionKey ) instead
				tr = Transaction(cx);
			} catch (Error& e) {
				Void _ = wait( tr.onError(e) );
			}
		}
	}
}

ACTOR Future<vector<std::pair<StorageServerInterface, ProcessClass>>> getServerListAndProcessClasses( Transaction *tr ) {
	state Future<vector<ProcessData>> workers = getWorkers(tr);
	state Future<Standalone<RangeResultRef>> serverList = tr->getRange( serverListKeys, CLIENT_KNOBS->TOO_MANY );
	Void _ = wait( success(workers) && success(serverList) );
	ASSERT( !serverList.get().more && serverList.get().size() < CLIENT_KNOBS->TOO_MANY );

	std::map<Optional<Standalone<StringRef>>, ProcessData> id_data;
	for( int i = 0; i < workers.get().size(); i++ )
		id_data[workers.get()[i].locality.processId()] = workers.get()[i];

	vector<std::pair<StorageServerInterface, ProcessClass>> results;
	for( int i = 0; i < serverList.get().size(); i++ ) {
		auto ssi = decodeServerListValue( serverList.get()[i].value );
		results.push_back( std::make_pair(ssi, id_data[ssi.locality.processId()].processClass) );
	}

	return results;
}

ACTOR Future<Void> waitServerListChange( DDTeamCollection *self, Database cx, FutureStream<Void> serverRemoved ) {
	state Future<Void> checkSignal = delay(SERVER_KNOBS->SERVER_LIST_DELAY);
	state Future<vector<std::pair<StorageServerInterface, ProcessClass>>> serverListAndProcessClasses = Never();
	state bool isFetchingResults = false;
	state Transaction tr(cx);
	loop {
		try {
			choose {
				when( Void _ = wait( checkSignal ) ) {
					checkSignal = Never();
					isFetchingResults = true;
					serverListAndProcessClasses = getServerListAndProcessClasses(&tr);
				}
				when( vector<std::pair<StorageServerInterface, ProcessClass>> results = wait( serverListAndProcessClasses ) ) {
					serverListAndProcessClasses = Never();
					isFetchingResults = false;

					for( int i = 0; i < results.size(); i++ ) {
						UID serverId = results[i].first.id();
						StorageServerInterface const& ssi = results[i].first;
						ProcessClass const& processClass = results[i].second;
						if (!self->shouldHandleServer(ssi)) {
							continue;
						}
						else if( self->server_info.count( serverId ) ) {
							auto& serverInfo = self->server_info[ serverId ];
							if (ssi.getValue.getEndpoint() != serverInfo->lastKnownInterface.getValue.getEndpoint() || processClass != serverInfo->lastKnownClass.classType()) {
								Promise<std::pair<StorageServerInterface, ProcessClass>> currentInterfaceChanged = serverInfo->interfaceChanged;
								serverInfo->interfaceChanged = Promise<std::pair<StorageServerInterface, ProcessClass>>();
								serverInfo->onInterfaceChanged = Future<std::pair<StorageServerInterface, ProcessClass>>( serverInfo->interfaceChanged.getFuture() );
								currentInterfaceChanged.send( std::make_pair(ssi,processClass) );
							}
						} else if( !self->recruitingIds.count(ssi.id()) ) {
							self->addServer( ssi, processClass, self->serverTrackerErrorOut );
							self->doBuildTeams = true;
						}
					}

					tr = Transaction(cx);
					checkSignal = delay(SERVER_KNOBS->SERVER_LIST_DELAY);
				}
				when( Void _ = waitNext( serverRemoved ) ) {
					if( isFetchingResults ) {
						tr = Transaction(cx);
						serverListAndProcessClasses = getServerListAndProcessClasses(&tr);
					}
				}
			}
		} catch(Error& e) {
			Void _ = wait( tr.onError(e) );
			serverListAndProcessClasses = Never();
			isFetchingResults = false;
			checkSignal = Void();
		}
	}
}

ACTOR Future<Void> serverMetricsPolling( TCServerInfo *server) {
	state double lastUpdate = now();
	loop {
		Void _ = wait( updateServerMetrics( server ) );
		Void _ = wait( delayUntil( lastUpdate + SERVER_KNOBS->STORAGE_METRICS_POLLING_DELAY + SERVER_KNOBS->STORAGE_METRICS_RANDOM_DELAY * g_random->random01(), TaskDataDistributionLaunch ) );
		lastUpdate = now();
	}
}

//Returns the KeyValueStoreType of server if it is different from self->storeType
ACTOR Future<KeyValueStoreType> keyValueStoreTypeTracker(DDTeamCollection *self, TCServerInfo *server) {
	state KeyValueStoreType type = wait(brokenPromiseToNever(server->lastKnownInterface.getKeyValueStoreType.getReplyWithTaskID<KeyValueStoreType>(TaskDataDistribution)));
	if(type == self->configuration.storageServerStoreType && (self->includedDCs.empty() || std::find(self->includedDCs.begin(), self->includedDCs.end(), server->lastKnownInterface.locality.dcId()) != self->includedDCs.end()) )
		Void _ = wait(Future<Void>(Never()));

	return type;
}

ACTOR Future<Void> storageServerTracker(
	DDTeamCollection *self,
	Database cx,
	TCServerInfo *server, //This actor is owned by this TCServerInfo
	ServerStatusMap *statusMap,
	MoveKeysLock lock,
	UID masterId,
	std::map<UID, Reference<TCServerInfo>>* other_servers,
	PromiseStream< std::pair<UID, Optional<StorageServerInterface>> > changes,
	PromiseStream<Void> serverFailures,
	Promise<Void> errorOut)
{
	state Future<Void> failureTracker;
	state ServerStatus status( false, false, server->lastKnownInterface.locality );
	state bool lastIsUndesired = false;
	state Future<Void> metricsTracker = serverMetricsPolling( server );
	state Future<std::pair<StorageServerInterface, ProcessClass>> interfaceChanged = server->onInterfaceChanged;

	state Future<KeyValueStoreType> storeTracker = keyValueStoreTypeTracker( self, server );
	state bool hasWrongStoreTypeOrDC = false;

	changes.send( std::make_pair(server->id, server->lastKnownInterface) );

	try {
		loop {
			status.isUndesired = false;
			status.isWrongConfiguration = false;

			// If there is any other server on this exact NetworkAddress, this server is undesired and will eventually be eliminated
			state std::vector<Future<Void>> otherChanges;
			std::vector<Promise<Void>> wakeUpTrackers;
			for(auto i = other_servers->begin(); i != other_servers->end(); ++i) {
				if (i->second.getPtr() != server && i->second->lastKnownInterface.address() == server->lastKnownInterface.address()) {
					auto& statusInfo = statusMap->get( i->first );
					TraceEvent("SameAddress", masterId)
						.detail("Failed", statusInfo.isFailed)
						.detail("Undesired", statusInfo.isUndesired)
						.detail("Server", server->id).detail("OtherServer", i->second->id)
						.detail("Address", server->lastKnownInterface.address())
						.detail("NumShards", self->shardsAffectedByTeamFailure->getNumberOfShards(server->id))
						.detail("OtherNumShards", self->shardsAffectedByTeamFailure->getNumberOfShards(i->second->id))
						.detail("OtherHealthy", !statusMap->get( i->second->id ).isUnhealthy());
					otherChanges.push_back( statusMap->onChange( i->second->id ) );
					if(!statusMap->get( i->second->id ).isUnhealthy()) {
						if(self->shardsAffectedByTeamFailure->getNumberOfShards(i->second->id) >= self->shardsAffectedByTeamFailure->getNumberOfShards(server->id))
						{
							TraceEvent(SevWarn, "UndesiredStorageServer", masterId)
								.detail("Server", server->id)
								.detail("Address", server->lastKnownInterface.address())
								.detail("OtherServer", i->second->id)
								.detail("NumShards", self->shardsAffectedByTeamFailure->getNumberOfShards(server->id))
								.detail("OtherNumShards", self->shardsAffectedByTeamFailure->getNumberOfShards(i->second->id));

							status.isUndesired = true;
						}
						else
							wakeUpTrackers.push_back(i->second->wakeUpTracker);
					}
				}
			}

			for(auto& p : wakeUpTrackers) {
				if( !p.isSet() )
					p.send(Void());
			}

			if( server->lastKnownClass.machineClassFitness( ProcessClass::Storage ) > ProcessClass::UnsetFit ) {
				if( self->optimalTeamCount > 0 ) {
					TraceEvent(SevWarn, "UndesiredStorageServer", masterId).detail("Server", server->id).detail("OptimalTeamCount", self->optimalTeamCount);
					status.isUndesired = true;
				}
				otherChanges.push_back( self->zeroOptimalTeams.onChange() );
			}

			//If this storage server has the wrong key-value store type, then mark it undesired so it will be replaced with a server having the correct type
			if(hasWrongStoreTypeOrDC) {
				TraceEvent(SevWarn, "UndesiredStorageServer", masterId).detail("Server", server->id).detail("StoreType", "?");
				status.isUndesired = true;
				status.isWrongConfiguration = true;
			}

			// If the storage server is in the excluded servers list, it is undesired
			NetworkAddress a = server->lastKnownInterface.address();
			AddressExclusion addr( a.ip, a.port );
			AddressExclusion ipaddr( a.ip );
			if (self->excludedServers.get( addr ) || self->excludedServers.get( ipaddr )) {
				TraceEvent(SevWarn, "UndesiredStorageServer", masterId).detail("Server", server->id)
					.detail("Excluded", self->excludedServers.get( addr ) ? addr.toString() : ipaddr.toString());
				status.isUndesired = true;
				status.isWrongConfiguration = true;
			}
			otherChanges.push_back( self->excludedServers.onChange( addr ) );
			otherChanges.push_back( self->excludedServers.onChange( ipaddr ) );

			failureTracker = storageServerFailureTracker( cx, server->lastKnownInterface, statusMap, &status, serverFailures, &self->unhealthyServers, masterId );

			//We need to recruit new storage servers if the key value store type has changed
			if(hasWrongStoreTypeOrDC)
				self->restartRecruiting.trigger();

			if( lastIsUndesired && !status.isUndesired )
				self->doBuildTeams = true;
			lastIsUndesired = status.isUndesired;

			choose {
				when( Void _ = wait( failureTracker ) ) {
					// The server is failed AND all data has been removed from it, so permanently remove it.
					TraceEvent("StatusMapChange", masterId).detail("ServerID", server->id).detail("Status", "Removing");
					changes.send( std::make_pair(server->id, Optional<StorageServerInterface>()) );

					// Remove server from FF/serverList
					Void _ = wait( removeStorageServer( cx, server->id, lock ) );

					TraceEvent("StatusMapChange", masterId).detail("ServerID", server->id).detail("Status", "Removed");
					// Sets removeSignal (alerting dataDistributionTeamCollection to remove the storage server from its own data structures)
					server->removed.send( Void() );
					self->removedServers.send( server->id );
					return Void();
				}
				when( std::pair<StorageServerInterface, ProcessClass> newInterface = wait( interfaceChanged ) ) {
					bool restartRecruiting =  newInterface.first.waitFailure.getEndpoint().address != server->lastKnownInterface.waitFailure.getEndpoint().address;
					TraceEvent("StorageServerInterfaceChanged", masterId).detail("ServerID", server->id)
						.detail("NewWaitFailureToken", newInterface.first.waitFailure.getEndpoint().token)
						.detail("OldWaitFailureToken", server->lastKnownInterface.waitFailure.getEndpoint().token);
					server->lastKnownInterface = newInterface.first;
					server->lastKnownClass = newInterface.second;
					interfaceChanged = server->onInterfaceChanged;
					changes.send( std::make_pair(server->id, server->lastKnownInterface) );
					// We rely on the old failureTracker being actorCancelled since the old actor now has a pointer to an invalid location
					status = ServerStatus( status.isFailed, status.isUndesired, server->lastKnownInterface.locality );

					//Restart the storeTracker for the new interface
					storeTracker = keyValueStoreTypeTracker(self, server);
					hasWrongStoreTypeOrDC = false;
					self->restartTeamBuilder.trigger();
					if(restartRecruiting)
						self->restartRecruiting.trigger();
				}
				when( Void _ = wait( otherChanges.empty() ? Never() : quorum( otherChanges, 1 ) ) ) {
					TraceEvent("SameAddressChangedStatus", masterId).detail("ServerID", server->id);
				}
				when( KeyValueStoreType type = wait( storeTracker ) ) {
					TraceEvent("KeyValueStoreTypeChanged", masterId)
						.detail("ServerID", server->id)
						.detail("StoreType", type.toString())
						.detail("DesiredType", self->configuration.storageServerStoreType.toString());
					TEST(true); //KeyValueStore type changed

					storeTracker = Never();
					hasWrongStoreTypeOrDC = true;
				}
				when( Void _ = wait( server->wakeUpTracker.getFuture() ) ) {
					server->wakeUpTracker = Promise<Void>();
				}
			}
		}
	} catch( Error &e ) {
		if (e.code() != error_code_actor_cancelled)
			errorOut.sendError(e);
		throw;
	}
}

//Monitor whether or not storage servers are being recruited.  If so, then a database cannot be considered quiet
ACTOR Future<Void> monitorStorageServerRecruitment(DDTeamCollection *self) {
	state bool recruiting = false;
	TraceEvent("StorageServerRecruitment", self->masterId)
		.detail("State", "Idle")
		.trackLatest((self->cx->dbName.toString() + "/StorageServerRecruitment_" + self->masterId.toString()).c_str());
	loop {
		if( !recruiting ) {
			while(self->recruitingStream.get() == 0) {
				Void _ = wait( self->recruitingStream.onChange() );
			}
			TraceEvent("StorageServerRecruitment", self->masterId)
				.detail("State", "Recruiting")
				.trackLatest((self->cx->dbName.toString() + "/StorageServerRecruitment_" + self->masterId.toString()).c_str());
			recruiting = true;
		} else {
			loop {
				choose {
					when( Void _ = wait( self->recruitingStream.onChange() ) ) {}
					when( Void _ = wait( self->recruitingStream.get() == 0 ? delay(SERVER_KNOBS->RECRUITMENT_IDLE_DELAY, TaskDataDistribution) : Future<Void>(Never()) ) ) { break; }
				}
			}
			TraceEvent("StorageServerRecruitment", self->masterId)
				.detail("State", "Idle")
				.trackLatest((self->cx->dbName.toString() + "/StorageServerRecruitment_" + self->masterId.toString()).c_str());
			recruiting = false;
		}
	}
}

ACTOR Future<Void> initializeStorage( DDTeamCollection *self, RecruitStorageReply candidateWorker ) {
	// SOMEDAY: Cluster controller waits for availability, retry quickly if a server's Locality changes
	self->recruitingStream.set(self->recruitingStream.get()+1);

	state UID interfaceId = g_random->randomUniqueID();
	InitializeStorageRequest isr;
	isr.storeType = self->configuration.storageServerStoreType;
	isr.seedTag = invalidTag;
	isr.reqId = g_random->randomUniqueID();
	isr.interfaceId = interfaceId;

	TraceEvent("DDRecruiting").detail("State", "Sending request to worker").detail("WorkerID", candidateWorker.worker.id())
		.detail("WorkerLocality", candidateWorker.worker.locality.toString()).detail("interf", interfaceId).detail("addr", candidateWorker.worker.address());

	self->recruitingIds.insert(interfaceId);
	self->recruitingLocalities.insert(candidateWorker.worker.address());
	ErrorOr<StorageServerInterface> newServer = wait( candidateWorker.worker.storage.tryGetReply( isr, TaskDataDistribution ) );
	self->recruitingIds.erase(interfaceId);
	self->recruitingLocalities.erase(candidateWorker.worker.address());

	self->recruitingStream.set(self->recruitingStream.get()-1);

	TraceEvent("DDRecruiting").detail("State", "Finished request").detail("WorkerID", candidateWorker.worker.id())
		.detail("WorkerLocality", candidateWorker.worker.locality.toString()).detail("interf", interfaceId).detail("addr", candidateWorker.worker.address());

	if( newServer.isError() ) {
		TraceEvent(SevWarn, "DDRecruitmentError").error(newServer.getError());
		if( !newServer.isError( error_code_recruitment_failed ) && !newServer.isError( error_code_request_maybe_delivered ) )
			throw newServer.getError();
		Void _ = wait( delay(SERVER_KNOBS->STORAGE_RECRUITMENT_DELAY, TaskDataDistribution) );
	}
	else if( newServer.present() ) {
		if( !self->server_info.count( newServer.get().id() ) )
			self->addServer( newServer.get(), candidateWorker.processClass, self->serverTrackerErrorOut );
		else
			TraceEvent(SevWarn, "DDRecruitmentError").detail("Reason", "Server ID already recruited");

		self->doBuildTeams = true;
		if( self->healthyTeamCount == 0 ) {
			Void _ = wait( self->checkBuildTeams( self ) );
		}
	}

	self->restartRecruiting.trigger();

	return Void();
}

ACTOR Future<Void> storageRecruiter( DDTeamCollection *self, Reference<AsyncVar<struct ServerDBInfo>> db ) {
	state Future<RecruitStorageReply> fCandidateWorker;
	state RecruitStorageRequest lastRequest;
	loop {
		try {
			RecruitStorageRequest rsr;
			std::set<AddressExclusion> exclusions;
			for(auto s = self->server_info.begin(); s != self->server_info.end(); ++s) {
				auto serverStatus = self->server_status.get( s->second->lastKnownInterface.id() );
				if( serverStatus.excludeOnRecruit() ) {
					TraceEvent("DDRecruitExcl1").detail("Excluding", s->second->lastKnownInterface.address());
					auto addr = s->second->lastKnownInterface.address();
					exclusions.insert( AddressExclusion( addr.ip, addr.port ) );
				}
			}
			for(auto addr : self->recruitingLocalities) {
				exclusions.insert( AddressExclusion(addr.ip, addr.port));
			}

			auto excl = self->excludedServers.getKeys();
			for(auto& s : excl)
				if (self->excludedServers.get(s)) {
					TraceEvent("DDRecruitExcl2").detail("Excluding", s.toString());
					exclusions.insert( s );
				}
			rsr.criticalRecruitment = self->healthyTeamCount == 0;
			for(auto it : exclusions) {
				rsr.excludeAddresses.push_back(it);
			}

			rsr.includeDCs = self->includedDCs;

			TraceEvent(rsr.criticalRecruitment ? SevWarn : SevInfo, "DDRecruiting").detail("State", "Sending request to CC")
			.detail("Exclusions", rsr.excludeAddresses.size()).detail("Critical", rsr.criticalRecruitment);

			if( rsr.criticalRecruitment ) {
				TraceEvent(SevWarn, "DDRecruitingEmergency", self->masterId);
			}

			if(!fCandidateWorker.isValid() || fCandidateWorker.isReady() || rsr.excludeAddresses != lastRequest.excludeAddresses || rsr.criticalRecruitment != lastRequest.criticalRecruitment) {
				lastRequest = rsr;
				fCandidateWorker = brokenPromiseToNever( db->get().clusterInterface.recruitStorage.getReply( rsr, TaskDataDistribution ) );
			}

			choose {
				when( RecruitStorageReply candidateWorker = wait( fCandidateWorker ) ) {
					self->addActor.send(initializeStorage(self, candidateWorker));
				}
				when( Void _ = wait( db->onChange() ) ) { // SOMEDAY: only if clusterInterface changes?
					fCandidateWorker = Future<RecruitStorageReply>();
				}
				when( Void _ = wait( self->restartRecruiting.onTrigger() ) ) {}
			}
		} catch( Error &e ) {
			if(e.code() != error_code_timed_out) {
				throw;
			}
			TEST(true); //Storage recruitment timed out
		}
	}
}

// Keep track of servers and teams -- serves requests for getRandomTeam
ACTOR Future<Void> dataDistributionTeamCollection(
	Reference<InitialDataDistribution> initData,
	TeamCollectionInterface tci,
	Database cx,
	Reference<AsyncVar<struct ServerDBInfo>> db,
	Reference<ShardsAffectedByTeamFailure> shardsAffectedByTeamFailure,
	MoveKeysLock lock,
	PromiseStream<RelocateShard> output,
	UID masterId,
	DatabaseConfiguration configuration,
	std::vector<Optional<Key>> includedDCs,
	Optional<std::vector<Optional<Key>>> otherTrackedDCs,
	PromiseStream< std::pair<UID, Optional<StorageServerInterface>> > serverChanges,
	Future<Void> readyToStart,
	Reference<AsyncVar<bool>> zeroHealthyTeams )
{
	state DDTeamCollection self( cx, masterId, lock, output, shardsAffectedByTeamFailure, configuration, includedDCs, otherTrackedDCs, serverChanges, readyToStart, zeroHealthyTeams );
	state Future<Void> loggingTrigger = Void();
	state PromiseStream<Void> serverRemoved;
	state Future<Void> interfaceChanges;
	state Future<Void> error = actorCollection( self.addActor.getFuture() );
	state Future<Void> storageServerRecruitment;
	state Future<Void> storageServerRecruitmentMonitor;
	state Future<Void> trackExcluded;

	Void _ = wait( readyToStart );

	try {
		self.init( *initData );
		initData = Reference<InitialDataDistribution>();
		storageServerRecruitment = storageRecruiter( &self, db );
		storageServerRecruitmentMonitor = monitorStorageServerRecruitment( &self );
		interfaceChanges = waitServerListChange( &self, cx, serverRemoved.getFuture() );
		trackExcluded = trackExcludedServers( &self, cx );

		// SOMEDAY: Monitor FF/serverList for (new) servers that aren't in allServers and add or remove them

		loop choose {

			when( GetTeamRequest req = waitNext(tci.getTeam.getFuture()) ) {
				self.addActor.send( self.getTeam( &self, req ) );
			}
			when( UID removedServer = waitNext( self.removedServers.getFuture() ) ) {
				TEST(true);  // Storage server removed from database
				self.removeServer( removedServer );
				serverRemoved.send( Void() );

				self.restartRecruiting.trigger();
			}
			when( Void _ = wait( self.zeroHealthyTeams->onChange() ) ) {
				if(self.zeroHealthyTeams->get()) {
					self.restartRecruiting.trigger();
					self.noHealthyTeams();
				}
			}
			when( Void _ = waitNext( self.serverFailures.getFuture() ) ) {
				self.restartRecruiting.trigger();
			}
			when( Void _ = wait( loggingTrigger ) ) {
				TraceEvent("TotalDataInFlight", masterId).detail("TotalBytes", self.getDebugTotalDataInFlight()).detail("UnhealthyServers", self.unhealthyServers).trackLatest(
					(cx->dbName.toString() + "/TotalDataInFlight").c_str());
				loggingTrigger = delay( SERVER_KNOBS->DATA_DISTRIBUTION_LOGGING_INTERVAL );
				self.countHealthyTeams();
			}
			when( Void _ = wait( self.serverTrackerErrorOut.getFuture() ) ) {} // Propagate errors from storageServerTracker
			when( Void _ = wait( interfaceChanges ) ) {}
			when( Void _ = wait( trackExcluded ) ) {}
			when( Void _ = wait( error ) ) {}
			when( Void _ = wait( storageServerRecruitment ) ) {}
		}
	} catch (Error& e) {
		if (e.code() != error_code_movekeys_conflict)
			TraceEvent(SevError, "dataDistributionTeamCollectionError", masterId).error(e);
		throw e;
	}
}

ACTOR Future<Void> waitForDataDistributionEnabled( Database cx ) {
	state Transaction tr(cx);
	loop {
		Void _ = wait(delay(SERVER_KNOBS->DD_ENABLED_CHECK_DELAY, TaskDataDistribution));

		try {
			Optional<Value> mode = wait( tr.get( dataDistributionModeKey ) );
			if (!mode.present()) return Void();
			if (mode.present()) {
				BinaryReader rd( mode.get(), Unversioned() );
				int m;
				rd >> m;
				if (m) return Void();
			}

			tr.reset();
		} catch (Error& e) {
			Void _ = wait( tr.onError(e) );
		}
	}
}

ACTOR Future<bool> isDataDistributionEnabled( Database cx ) {
	state Transaction tr(cx);
	loop {
		try {
			Optional<Value> mode = wait( tr.get( dataDistributionModeKey ) );
			if (!mode.present()) return true;
			if (mode.present()) {
				BinaryReader rd( mode.get(), Unversioned() );
				int m;
				rd >> m;
				if (m) return true;
			}
			// SOMEDAY: Write a wrapper in MoveKeys.h
			Optional<Value> readVal = wait( tr.get( moveKeysLockOwnerKey ) );
			UID currentOwner = readVal.present() ? BinaryReader::fromStringRef<UID>(readVal.get(), Unversioned()) : UID();
			if( currentOwner != dataDistributionModeLock )
				return true;
			return false;
		} catch (Error& e) {
			Void _ = wait( tr.onError(e) );
		}
	}
}

//Ensures that the serverKeys key space is properly coalesced
//This method is only used for testing and is not implemented in a manner that is safe for large databases
ACTOR Future<Void> debugCheckCoalescing(Database cx) {
	state Transaction tr(cx);
	loop {
		try {
			state Standalone<RangeResultRef> serverList = wait(tr.getRange(serverListKeys, CLIENT_KNOBS->TOO_MANY));
			ASSERT( !serverList.more && serverList.size() < CLIENT_KNOBS->TOO_MANY);

			state int i;
			for(i = 0; i < serverList.size(); i++) {
				state UID id = decodeServerListValue(serverList[i].value).id();
				Standalone<RangeResultRef> ranges = wait(krmGetRanges(&tr, serverKeysPrefixFor(id), allKeys));
				ASSERT(ranges.end()[-1].key == allKeys.end);

				for(int j = 0; j < ranges.size() - 2; j++)
					if(ranges[j].value == ranges[j + 1].value)
						TraceEvent(SevError, "UncoalescedValues", id).detail("Key1", printable(ranges[j].key)).detail("Key2", printable(ranges[j + 1].key)).detail("Value", printable(ranges[j].value));
			}

			TraceEvent("DoneCheckingCoalescing");
			return Void();
		}
		catch(Error &e){
			Void _ = wait( tr.onError(e) );
		}
	}
}

static std::set<int> const& normalDDQueueErrors() {
	static std::set<int> s;
	if (s.empty()) {
		s.insert( error_code_movekeys_conflict );
		s.insert( error_code_broken_promise );
	}
	return s;
}

ACTOR Future<Void> popOldTags( Transaction* tr, Reference<ILogSystem> logSystem, Version recoveryCommitVersion, int8_t tagLocality, std::vector<Tag> tags ) {
	Optional<Standalone<StringRef>> val = wait( tr->get( tagLocality == tagLocalityUpgraded ? serverTagMaxOldKey : serverMaxTagKeyFor(tagLocality) ) );
	if(!val.present())
		return Void();

	state Tag maxTag = tagLocality == tagLocalityUpgraded ? decodeServerTagMaxValueOld(val.get()) : decodeServerTagMaxValue( val.get() );

	std::set<Tag> unusedTags;
	for(uint16_t i = 0; i <= maxTag.id; i++)
		unusedTags.insert(Tag(tagLocality, i));

	for(Tag& t : tags) {
		if(t.locality == tagLocality) {
			unusedTags.erase(t);
		}
	}

	for(auto tag : unusedTags)
		logSystem->pop(recoveryCommitVersion, tag);

	return Void();
}

ACTOR Future<Void> popOldTags( Database cx, Reference<ILogSystem> logSystem, Version recoveryCommitVersion ) {
	state Transaction tr(cx);

	if( recoveryCommitVersion == 1 )
		return Void();

	loop {
		try {
			state Future<Standalone<RangeResultRef>> fTagLocalities = tr.getRange( tagLocalityListKeys, CLIENT_KNOBS->TOO_MANY );
			state Future<Standalone<RangeResultRef>> fTags = tr.getRange( serverTagKeys, CLIENT_KNOBS->TOO_MANY );
			state Future<Standalone<RangeResultRef>> fHistoryTags = tr.getRange( serverTagHistoryKeys, CLIENT_KNOBS->TOO_MANY );

			Void _ = wait( success(fTagLocalities) && success(fTags) && success(fHistoryTags) );

			state std::vector<Future<Void>> popActors;
			state std::vector<Tag> tags;

			for(auto& kv : fTags.get()) {
				tags.push_back(decodeServerTagValue( kv.value ));
			}

			for(auto& kv : fHistoryTags.get()) {
				tags.push_back(decodeServerTagValue( kv.value ));
			}

			//FIXME: we have to check the old locality indefinately, because we can never be sure when pops have succeeded, we can remove this code when we no longer need to support upgrades from 5.X to 6.0
			popActors.push_back(popOldTags(&tr, logSystem, recoveryCommitVersion, tagLocalityUpgraded, tags));
			for(auto& kv : fTagLocalities.get()) {
				popActors.push_back(popOldTags(&tr, logSystem, recoveryCommitVersion, decodeTagLocalityListValue(kv.value), tags));
			}
			Void _ = wait( waitForAll(popActors) );
			return Void();
		} catch( Error &e ) {
			Void _ = wait( tr.onError(e) );
		}
	}
}

ACTOR Future<Void> pollMoveKeysLock( Database cx, MoveKeysLock lock ) {
	loop {
		Void _ = wait(delay(SERVER_KNOBS->MOVEKEYS_LOCK_POLLING_DELAY));
		state Transaction tr(cx);
		loop {
			try {
				Void _ = wait( checkMoveKeysLockReadOnly(&tr, lock) );
				break;
			} catch( Error &e ) {
				Void _ = wait( tr.onError(e) );
			}
		}
	}
}

ACTOR Future<Void> dataDistribution(
		Reference<AsyncVar<struct ServerDBInfo>> db,
		MasterInterface mi, DatabaseConfiguration configuration,
		PromiseStream< std::pair<UID, Optional<StorageServerInterface>> > serverChanges,
		Reference<ILogSystem> logSystem,
		Version recoveryCommitVersion,
		std::vector<Optional<Key>> primaryDcId,
		std::vector<Optional<Key>> remoteDcId,
		double* lastLimited)
{
	state Database cx = openDBOnServer(db, TaskDataDistributionLaunch, true, true);
	cx->locationCacheSize = SERVER_KNOBS->DD_LOCATION_CACHE_SIZE;

	state Transaction trVer(cx);
	loop {
		try {
			trVer.setOption( FDBTransactionOptions::ACCESS_SYSTEM_KEYS );
			trVer.setOption( FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE );

			if( !g_network->isSimulated() ) {
				UID id(g_random->randomUniqueID());
				TraceEvent("UpgradeProcessClassTransaction", mi.id())
					.detail("TransactionUID", id);
				trVer.debugTransaction( id );
			}

			Optional<Value> val = wait(trVer.get(processClassVersionKey));

			if (val.present())
				break;

			Standalone<RangeResultRef> processClasses = wait( trVer.getRange( processClassKeys, CLIENT_KNOBS->TOO_MANY ) );
			ASSERT( !processClasses.more && processClasses.size() < CLIENT_KNOBS->TOO_MANY );

			trVer.clear(processClassKeys);
			trVer.set(processClassVersionKey, processClassVersionValue);
			for (auto it : processClasses) {
				UID processUid = decodeProcessClassKeyOld(it.key);
				trVer.set(processClassKeyFor(processUid.toString()), it.value);
			}

			Void _ = wait(trVer.commit());
			TraceEvent("ProcessClassUpgrade");
			break;
		}
		catch(Error &e) {
			Void _ = wait( trVer.onError(e) );
		}
	}


	//cx->setOption( FDBDatabaseOptions::LOCATION_CACHE_SIZE, StringRef((uint8_t*) &SERVER_KNOBS->DD_LOCATION_CACHE_SIZE, 8) );
	//ASSERT( cx->locationCacheSize == SERVER_KNOBS->DD_LOCATION_CACHE_SIZE );

	//Void _ = wait(debugCheckCoalescing(cx));

	loop {
		try {
			loop {
				TraceEvent("DDInitTakingMoveKeysLock", mi.id());
				state MoveKeysLock lock = wait( takeMoveKeysLock( cx, mi.id() ) );
				TraceEvent("DDInitTookMoveKeysLock", mi.id());
				state Reference<InitialDataDistribution> initData = wait( getInitialDataDistribution(cx, mi.id(), lock) );
				if(initData->shards.size() > 1) {
					TraceEvent("DDInitGotInitialDD", mi.id()).detail("b", printable(initData->shards.end()[-2].begin)).detail("e", printable(initData->shards.end()[-2].end)).detail("src", describe(initData->shards.end()[-2].value.first)).detail("dest", describe(initData->shards.end()[-2].value.second)).trackLatest("InitialDD");
				} else {
					TraceEvent("DDInitGotInitialDD", mi.id()).detail("b","").detail("e", "").detail("src", "[no items]").detail("dest", "[no items]").trackLatest("InitialDD");
				}

				if (initData->mode) break;
				TraceEvent("DataDistributionDisabled", mi.id());

				TraceEvent("MovingData", mi.id())
					.detail( "InFlight", 0 )
					.detail( "InQueue", 0 )
					.detail( "AverageShardSize", -1 )
					.detail( "LowPriorityRelocations", 0 )
					.detail( "HighPriorityRelocations", 0 )
					.detail( "HighestPriority", 0 )
					.trackLatest( format("%s/MovingData", printable(cx->dbName).c_str() ).c_str() );

				TraceEvent("TotalDataInFlight", mi.id()).detail("TotalBytes", 0)
					.trackLatest((cx->dbName.toString() + "/TotalDataInFlight").c_str());

				Void _ = wait( waitForDataDistributionEnabled(cx) );
				TraceEvent("DataDistributionEnabled");
			}

			// When/If this assertion fails, Evan owes Ben a pat on the back for his foresight
			ASSERT(configuration.storageTeamSize > 0);

			state PromiseStream<RelocateShard> output;
			state PromiseStream<Promise<int64_t>> getAverageShardBytes;
			state PromiseStream<GetMetricsRequest> getShardMetrics;
			state Promise<Void> readyToStart;

			vector<TeamCollectionInterface> tcis;
			Reference<AsyncVar<bool>> anyZeroHealthyTeams;
			vector<Reference<AsyncVar<bool>>> zeroHealthyTeams;
			tcis.push_back(TeamCollectionInterface());
			zeroHealthyTeams.push_back(Reference<AsyncVar<bool>>( new AsyncVar<bool>(true) ));
			int storageTeamSize = configuration.storageTeamSize;

			vector<Future<Void>> actors;
			if (configuration.remoteTLogReplicationFactor > 0) {
				tcis.push_back(TeamCollectionInterface());
				storageTeamSize = 2*configuration.storageTeamSize;

				zeroHealthyTeams.push_back( Reference<AsyncVar<bool>>( new AsyncVar<bool>(true) ) );
				anyZeroHealthyTeams = Reference<AsyncVar<bool>>( new AsyncVar<bool>(true) );
				actors.push_back( anyTrue(zeroHealthyTeams, anyZeroHealthyTeams) );
			} else {
				anyZeroHealthyTeams = zeroHealthyTeams[0];
			}

			Reference<ShardsAffectedByTeamFailure> shardsAffectedByTeamFailure( new ShardsAffectedByTeamFailure );

			actors.push_back( pollMoveKeysLock(cx, lock) );
			actors.push_back( popOldTags( cx, logSystem, recoveryCommitVersion) );
			actors.push_back( reportErrorsExcept( dataDistributionTracker( initData, cx, shardsAffectedByTeamFailure, output, getShardMetrics, getAverageShardBytes.getFuture(), readyToStart, anyZeroHealthyTeams, mi.id() ), "DDTracker", mi.id(), &normalDDQueueErrors() ) );
			actors.push_back( reportErrorsExcept( dataDistributionQueue( cx, output, getShardMetrics, tcis, shardsAffectedByTeamFailure, lock, getAverageShardBytes, mi, storageTeamSize, configuration.durableStorageQuorum, lastLimited ), "DDQueue", mi.id(), &normalDDQueueErrors() ) );
			actors.push_back( reportErrorsExcept( dataDistributionTeamCollection( initData, tcis[0], cx, db, shardsAffectedByTeamFailure, lock, output, mi.id(), configuration, primaryDcId, configuration.remoteTLogReplicationFactor > 0 ? remoteDcId : std::vector<Optional<Key>>(), serverChanges, readyToStart.getFuture(), zeroHealthyTeams[0] ), "DDTeamCollectionPrimary", mi.id(), &normalDDQueueErrors() ) );
			if (configuration.remoteTLogReplicationFactor > 0) {
				actors.push_back( reportErrorsExcept( dataDistributionTeamCollection( initData, tcis[1], cx, db, shardsAffectedByTeamFailure, lock, output, mi.id(), configuration, remoteDcId, Optional<std::vector<Optional<Key>>>(), serverChanges, readyToStart.getFuture(), zeroHealthyTeams[1] ), "DDTeamCollectionSecondary", mi.id(), &normalDDQueueErrors() ) );
			}

			Void _ = wait( waitForAll( actors ) );
			return Void();
		}
		catch( Error &e ) {
			state Error err = e;
			if( e.code() != error_code_movekeys_conflict )
				throw err;
			bool ddEnabled = wait( isDataDistributionEnabled(cx) );
			TraceEvent("DataDistributionMoveKeysConflict").detail("ddEnabled", ddEnabled);
			if( ddEnabled )
				throw err;
		}
	}
}

DDTeamCollection* testTeamCollection(int teamSize, IRepPolicyRef policy, int processCount) {
	Database database = DatabaseContext::create(
		Reference<AsyncVar<ClientDBInfo>>(new AsyncVar<ClientDBInfo>()),
		Never(),
		LocalityData(),
		false
	);

	DatabaseConfiguration conf;
	conf.storageTeamSize = teamSize;
	conf.storagePolicy = policy;

	DDTeamCollection* collection = new DDTeamCollection(
		database,
		UID(0, 0),
		MoveKeysLock(),
		PromiseStream<RelocateShard>(),
		Reference<ShardsAffectedByTeamFailure>(new ShardsAffectedByTeamFailure()),
		conf,
		{},
		{},
		PromiseStream<std::pair<UID, Optional<StorageServerInterface>>>(),
		Future<Void>(Void()),
		Reference<AsyncVar<bool>>( new AsyncVar<bool>(true) )
	);

	for(int id = 1; id <= processCount; id++) {
		UID uid(id, 0);
		StorageServerInterface interface;
		interface.uniqueID = uid;
	 	interface.locality.set(LiteralStringRef("machineid"), Standalone<StringRef>(std::to_string(id)));
		interface.locality.set(LiteralStringRef("zoneid"), Standalone<StringRef>(std::to_string(id % 5)));
		interface.locality.set(LiteralStringRef("data_hall"), Standalone<StringRef>(std::to_string(id % 3)));
		collection->server_info[uid] = Reference<TCServerInfo>(new TCServerInfo(
			interface,
			ProcessClass()
		));
	}

	return collection;
}

TEST_CASE("DataDistribution/AddAllTeams/isExhaustive") {
	IRepPolicyRef policy = IRepPolicyRef(new PolicyAcross(3, "zoneid", IRepPolicyRef(new PolicyOne())));
	state DDTeamCollection* collection = testTeamCollection(3, policy, 10);

	vector<UID> processes;
	for(auto process = collection->server_info.begin(); process != collection->server_info.end(); process++) {
		processes.push_back(process->first);
	}

	state vector<vector<UID>> teams;
	int result = wait(collection->addAllTeams(collection, processes, &teams, 200));
	delete(collection);

	for(int i = 0; i < teams.size(); i++) {
		auto team = teams[i];
	}
	ASSERT(result == 80);
	ASSERT(teams[0] == std::vector<UID>({ UID(1,0), UID(2,0), UID(3,0) }));
	ASSERT(teams[1] == std::vector<UID>({ UID(1,0), UID(2,0), UID(4,0) }));
	ASSERT(teams[2] == std::vector<UID>({ UID(1,0), UID(2,0), UID(5,0) }));
	ASSERT(teams[3] == std::vector<UID>({ UID(1,0), UID(2,0), UID(8,0) }));
	ASSERT(teams[4] == std::vector<UID>({ UID(1,0), UID(2,0), UID(9,0) }));
	ASSERT(teams[5] == std::vector<UID>({ UID(1,0), UID(2,0), UID(10,0) }));
	ASSERT(teams[6] == std::vector<UID>({ UID(1,0), UID(3,0), UID(4,0) }));
	ASSERT(teams[7] == std::vector<UID>({ UID(1,0), UID(3,0), UID(5,0) }));
	ASSERT(teams[8] == std::vector<UID>({ UID(1,0), UID(3,0), UID(7,0) }));
	ASSERT(teams[9] == std::vector<UID>({ UID(1,0), UID(3,0), UID(9,0) }));
	ASSERT(teams[10] == std::vector<UID>({ UID(1,0), UID(3,0), UID(10,0) }));
	ASSERT(teams[79] == std::vector<UID>({ UID(8,0), UID(9,0), UID(10,0) }));

	return Void();
}

TEST_CASE("DataDistribution/AddAllTeams/withLimit") {
	IRepPolicyRef policy = IRepPolicyRef(new PolicyAcross(3, "zoneid", IRepPolicyRef(new PolicyOne())));
	state DDTeamCollection* collection = testTeamCollection(3, policy, 10);

	vector<UID> processes;
	for(auto process = collection->server_info.begin(); process != collection->server_info.end(); process++) {
		processes.push_back(process->first);
	}

	state vector<vector<UID>> teams;
	int result = wait(collection->addAllTeams(collection, processes, &teams, 10));
	delete(collection);

	for(int i = 0; i < teams.size(); i++) {
		auto team = teams[i];
	}
	ASSERT(result == 10);
	ASSERT(teams[0] == std::vector<UID>({ UID(1,0), UID(2,0), UID(3,0) }));
	ASSERT(teams[1] == std::vector<UID>({ UID(1,0), UID(2,0), UID(4,0) }));
	ASSERT(teams[2] == std::vector<UID>({ UID(1,0), UID(2,0), UID(5,0) }));
	ASSERT(teams[3] == std::vector<UID>({ UID(1,0), UID(2,0), UID(8,0) }));
	ASSERT(teams[4] == std::vector<UID>({ UID(1,0), UID(2,0), UID(9,0) }));
	ASSERT(teams[5] == std::vector<UID>({ UID(1,0), UID(2,0), UID(10,0) }));
	ASSERT(teams[6] == std::vector<UID>({ UID(1,0), UID(3,0), UID(4,0) }));
	ASSERT(teams[7] == std::vector<UID>({ UID(1,0), UID(3,0), UID(5,0) }));
	ASSERT(teams[8] == std::vector<UID>({ UID(1,0), UID(3,0), UID(7,0) }));
	ASSERT(teams[9] == std::vector<UID>({ UID(1,0), UID(3,0), UID(9,0) }));

	return Void();
}

TEST_CASE("DataDistribution/AddTeamsBestOf/SkippingBusyServers") {
	Void _ = wait(Future<Void>(Void()));
	IRepPolicyRef policy = IRepPolicyRef(new PolicyAcross(3, "zoneid", IRepPolicyRef(new PolicyOne())));
	state DDTeamCollection* collection = testTeamCollection(3, policy, 10);

	collection->addTeam(std::set<UID>({ UID(1,0), UID(2,0), UID(3,0) }));
	collection->addTeam(std::set<UID>({ UID(1,0), UID(3,0), UID(4,0) }));

	int result = collection->addTeamsBestOf(8);

	ASSERT(result == 8);

	for(auto process = collection->server_info.begin(); process != collection->server_info.end(); process++) {
		auto teamCount = process->second->teams.size();
		ASSERT(teamCount >= 1);
		ASSERT(teamCount <= 5);
	}

	delete(collection);

	return Void();
}

TEST_CASE("DataDistribution/AddTeamsBestOf/NotEnoughServers") {
	Void _ = wait(Future<Void>(Void()));

	IRepPolicyRef policy = IRepPolicyRef(new PolicyAcross(3, "zoneid", IRepPolicyRef(new PolicyOne())));
	state DDTeamCollection* collection = testTeamCollection(3, policy, 5);

	collection->addTeam(std::set<UID>({ UID(1,0), UID(2,0), UID(3,0) }));
	collection->addTeam(std::set<UID>({ UID(1,0), UID(3,0), UID(4,0) }));

	int result = collection->addTeamsBestOf(10);
	delete(collection);

	ASSERT(result == 8);

	return Void();
}